WO2002087804A1 - Method and device for semi-automatic on-site production of metal tanks - Google Patents

Abstract

The invention concerns a method whereby a steel strip (41) derived from a roll is gradually straightened out, cambered and engaged on rollers (13) supported on cylinders (12), until, after the corresponding perimeter is obtained, the ends are separated and welded together, then in lifting with the actuators (12) said first hoop to a height sufficient for production, then gradually assembling by welding a second hoop by the above process. All those operations are managed by a programmable automaton.

Description

Semi-automatic production method and device, jïiejâ

The invention relates to a method and a device for semi-automatic production, on site, of large-capacity cylindrical metal tanks.

Economic problems arising for the production of large diameter steel tanks, because it is excluded, for reasons of space, to realize them elsewhere than on site, manufacturers are forced to open a specific site on the site of the establishment, by moving a sometimes large team of specialized workers (industrial boilermakers, welders, etc.) who only have basic equipment to carry out their task, facilitating training , flame cutting and welding of sheet metal plates whose dimensions must be limited, to facilitate handling and assembly. It results from this a waste of time resulting in high cost prices and problems, as for the respect of the deadline imposed by the principal, relative to the planning previously established with the representatives of the other trades.

A method and a device are already known for producing cylindrical tanks and ferrules from sheet metal, such as those described in European patent n ° 0136581 with which the ferrules are obtained by plating strips of sheet metal against the edge of a turntable, of appropriate diameter, on which the said strips are introduced progressively as the reel unwinds and the sheet metal straightens.

This method 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.

There is also known a process and a device for semi-automatic production of reservoirs and ferrules corresponding to the preamble of claim 1 (European patent n ° 0727264). The method consists in carrying out, in order, the following operations:

a) Creation of a first ferrule. b) Installation and securing of a roof on the first shell. c) Lifting of the assembly carried out in the previous operation to a height corresponding to the width of the sheet metal strip. d) Creation of a second ferrule under the first. e) Progressive joining of the shell made in operation (a) to that made in the previous operation (d). f) Repeat operations (c) (d) and (e) as many times as necessary to obtain the desired tank height. g) Installation of the assembly, carried out by following the above operations on a diameter bottom corresponding and joining it to the last shell.

The ferrules are produced by bending, bending, as the drive and unwinding of the sheet metal coil progress. During the production of a ferrule, directly under the previous one, the sheet metal strip is progressively secured to the preceding coil, which it drives in rotation, this securing being preceded by an equally progressive abutment of this preceding ferrule on the edge of the strip of sheet metal being scrolled until complete completion of this next ferrule. The bending of the sheet metal strip, according to the required radius, is constantly ensured, as it is driven and scrolled.

The device for applying the process mentioned above is mainly characterized by the use of means for driving and bending a strip of sheet metal from a roller and rollers associated with lifting cylinders distributed regularly over a circumference to constitute a merry-go-round, of diameter corresponding to that of the ferrules to be produced, intended to gradually support the sheet after bending, the sheet being driven by a tractor with motorized rollers.

If the method and the device as they have just been described, undeniably allows the production of the ferrules directly from sheet metal rolls, while respecting the radius sufficiently precisely required and the concordance of ferrules in order to obtain a rigorous seal at each level, they do not, however, by themselves, reduce the number of skilled workers or have a decisive influence on the duration of achievement.

The object of the present invention is to remedy these drawbacks. This invention as characterized in the claims, solves the problem of defining a method and creating a device allowing semi-automatic production in a very short time, by a very small number of specialized workers, of high capacity sheet metal, from rolls of commercial sheet metal.

The process for producing large-capacity cylindrical metal tanks on sites, from sheet metal coils using a means for driving, bending and running the sheet metal strip as well as means for transverse cutting, docking and longitudinal welding of the sheet metal strips, consisting of making the ferrules by bending, progressive bending as a function of the desired diameter, as the drive and the unwinding of the sheet metal strip progressively and successively making the ferrules from the top downwards by making each of them directly under the previous one by driving the latter in rotation by progressive joining of the sheet metal strip during forming, this joining being preceded an equally progressive pressing of the previous ferrule on the edge of the sheet metal strip during the scrolling until complete completion of the following ferrule, the roof being fixed on the upper edge of the first ferrule after completion of this or the first two ferrules; the wall being secured to the bottom as soon as it has reached the desired height, is characterized, according to the invention, mainly:

1) in that the production of the ferrules is preceded by the following operations:

a) Realization of a bottom by circular flame cutting of an assembly of sheet metal strips previously joined laterally by reference to a point C, determined arbitrarily on the surface of this assembly of sheets.

b) Materialization of the axis of symmetry of the ferrules by welding of a vertical axis reference device Y exactly coinciding with the point C defined on the bottom surface in the previous step.

c) Precise positioning, relative to the Y axis of the reference device, of all the means contributing to the drive, to the travel, to the guidance, to the docking and to the welding of the sheet metal strips and to the lifting of the together as and when they are made. 2) In that the vertical position of the scrolling rollers of the lifting means is controlled remotely very precisely, individually and collectively, as a function of the progress of the assembly operations and the sequences imposed by them.

3 °) In that the respective position of the internal and external welding devices is permanently indicated very precisely during their use, with immediate indication of the offsets that may appear between the two devices, so that this offset can be immediately canceled in order to permanently maintain perfect concordance of the internal and external welding points during the progression of this weld bead in the ledge.

4 °) In that the joining by welding of the roof on the corresponding edge of the upper shell is accompanied by the rotation of the assembly over 360 ° at a controlled speed compatible with the ideal progression of the weld bead.

5 °) In that the welding of the assembly on the bottom is preceded by the pressing on movable cleats of the free edge of the lower ferrule, the disassembly of the scroll rollers, the coordinated movement downwards of said movable cleats until the said free edge of the lower ferrule rests on the periphery of the bottom, then the discharge through the hole of man unusable equipment for this final operation.

The device according to the invention, allowing the application of the process described above, is mainly characterized in that all the means used for the unwinding, straightening, forming, driving, cutting, welding and lifting, are managed by a programmable automaton, remotely controllable by a wireless control unit, respecting predetermined data.

The position of the electrodes of the welding devices is controlled by detectors connected to a monitor which measures and displays, in real time, any position deviations with a view to their immediate cancellation.

The advantages obtained, thanks to this invention, essentially consist in that all the parameters of forming, cutting, assembly and welding are determined very precisely beforehand and introduced into the programmable controller before the opening of the site, while leaving operators control of the entire process by means of non-wired remote control means, which therefore makes it possible to move only a very limited number of people to sites, most often reduced to three, while reducing the completion time given

1 prior elimination of previous downtime resulting from the preparation of adjustments, handling and trial and error.

Other characteristics and advantages will appear in the following description of a process and a device for producing tanks intended for the chemical industry, given by way of nonlimiting example with regard to the appended drawings, in which:

- Figures 1 to 6 schematically illustrate the main steps of the process.

Figure 7 shows a schematic elevational view of a tank in progress.

Figure 8 shows a schematic partial top view of a ferrule in progress.

- Figure 9 shows a top view of the unwinding system for cutting, docking and welding.

The device for producing tanks, according to the invention, mainly comprises a carousel 10 consisting of a base 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 supporting the reel holder, as well as the unwinding and bending machine 30 essentially consisting of three rollers 31, 32, 33 including one 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 movement of the sheet 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 secured to each other and comprising, at their free end, a calibrated roller, said calibrated rollers being permanently biased against the outer face of the sheet by a compass returned to the open position by a gas spring, and secondly, as regards the control of the movement of the sheet 41, of a coding wheel 60 biased against the outer face of the sheet 41 by an arm articulated with respect to the axis of connection of the end of the rod of the gas spring to the articulated element of the compass, a transverse cutting station 70, a sheet docking station 80 consisting of rollers 81 located outside the carousel 10 and rollers 82 situated inside the latter, in concordance with each other, a longitudinal welding station 90, with internal 91 and external welding device 92 and a motorized roller tractor 100.

By examining Figures 1 to 6 in more detail, illustrating the main steps of the process used, in the light of Figures 7, 8 and 9, it is noted that a first ferrule 42 is first produced by driving 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 carousel 10, until the perimeter corresponding to the chosen diameter is reached, the cutting station 70 then cuts the sheet metal strip 41 to separate it from the coil 40, the vertical assembly and the corresponding welding are then carried out, the first ferrule 42 is then completed. Then, as shown in FIG. 2, it suffices 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, of a corresponding height. to the width of a strip of sheet metal, to allow, by successive engagement, the presentation of a new strip of sheet metal 41 on the rollers 13 of the jacks 12 progressively lowered, as the sheet metal 41 travels, as show in Figures 4 and 5, to obtain the realization of a second ferrule 43, fully supporting the first ferrule 42 equipped with its roof 44, as shown in Figure 6, this by proceeding in all respects as indicated above 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 using the jacks 12 associated with the rollers constituting the merry-go-round, with a view to adding a third ferrule , proceeding as illustrated in Figures 3 to 6. During the unwinding again, to make the additional ferrule (s) 43, the sheet metal strip 41 is engaged, as we have just seen, under the first ferrule 42, then docked using the rollers 81, 82 of the station d 'docking 80, which thus presses 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 advancement of prison. The running of the sheet metal strip 41 is stopped before each post of the carousel 10, 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 the seal 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 motorized rollers 81, 82 of the docking station 80.

Now examining FIG. 9 in relation to FIGS. 7 and 8, it is noted that, after having introduced into the programmable controller (not shown) the data relating to the diameters of ferrules to be produced and to the length of bands to be unwound, corresponding at the perimeter of said ferrule 42, an automatic function positions the bending roller 33 by means 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 control rectifying means 23, 36, 37 of the bending and scrolling radius 31, 32, 33 which will now be mentioned.

First of all, it is noted 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 of the deflection communicated to the sheet metal strip by the bending roller 33. Corrections, more or less, are thus permanently transmitted automatically to the system supply to the jack 35, ensuring the positioning of the bending roller 33. The coding wheel 60, for its part, continuously transmits 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 control, at the appropriate time, the precise stopping of the drive of the motorized rollers 31 and 32, preceding the command to initiate the cutting by the transve cutting station rsale 70, consisting of a slide 71 with motorized carriage 72, supporting a cutting tool 73. Referring now again to FIGS. 1 to 6 illustrating the process, it is noted that, as has already been mentioned above:

1 °) The production of the ferrules 42, 43 is preceded by the following operations:

a) Manufacture of a bottom 11 by circular flame cutting of an assembly of sheet metal strips, previously joined laterally, by reference to a point C arbitrarily determined on the surface of this assembly of sheet metal.

b) Materialization of the axis of symmetry of the ferrules 42, 43 by welding of a reference device, of vertical axis Y coinciding with the point C determined in the preceding step.

c) Precise positioning, relative to the Y axis of the reference device, using a template of all the means contributing to the drive, to the running, to the guidance, to the docking and to the welding of the bands sheet metal and lifting of the assembly as and when it is made.

2) The vertical position of the scroll rollers 13 of the lifting cylinders 12 is remotely controlled very precisely, individually and collectively, as a function of the progress of the assembly operations and the sequences imposed by the latter. 3 °) The respective position of the internal 91 and external 92 welding devices is permanently indicated very precisely during their use, with immediate indication on a monitor, offsets which may appear between the two welding devices 91, 92, so that this offset can be immediately canceled in order to permanently maintain perfect concordance of the internal and external weld points, during the progression of the weld bead.

4) The joining by welding of the roof 44 on the corresponding edge of the upper shell 42 is accompanied by the rotation of the assembly over 360 ° at a controlled speed compatible with the ideal progression of the weld bead.

5 °) The welding of the assembly on the bottom 11 is preceded by the pressing of the lower ferrule, on movable tabs replacing the scroll rollers 13 previously disassembled.

It is understood that in order to obtain perfect parallelism of the ferrules 42, 43 with one another and relative to the bottom 11 momentarily used as a reference, the actuators 12 for operating the scroll rollers 13 and the tabs (not shown) must be of strictly identical characteristics and that the oil flow rates to which they are subjected, both at the inlet and at the outlet, must be perfectly controlled in order to obtain very precise strokes of the cylinder rods.

Claims

1. Method for producing large-capacity cylindrical metal tanks on sites, from sheet metal coils (40) using a means (30) for driving, bending and running the sheet metal strip (41) as well that transverse cutting means (70), docking (80) and longitudinal welding (90) of the sheet metal strips, consisting in making the ferrules (42, 43) by bending, progressive bending as a function of the desired diameter, at as and when the sheet metal strip (41) is driven and unwound and successively make the ferrules (42, 43) from top to bottom by making each of them (42) directly under the previous one (43 ) by driving the latter in rotation by progressive joining of the sheet metal strip during forming, this joining being preceded by an equally progressive pressing of the previous ferrule (43) on the edge of the sheet metal strip ( 41) during scrolling to when the next ferrule (42) is completely produced, the roof (44) being fixed on the upper edge of the first ferrule (42) after completion of the latter or of the first two ferrules; the wall being secured to the bottom (11) as soon as it has reached the desired height, mainly characterized: 1 °) In that the production of the ferrules is preceded by the following operations: a) Making a bottom (11) by circular flame cutting of an assembly of sheet metal strips, previously joined laterally, by reference to a point C arbitrarily determined on the surface of this assembly of sheets. b) Materialization of the axis of symmetry of the ferrules by welding of a reference device, of vertical axis Y coinciding exactly with the point C defined on the bottom surface (11) in the previous step. c) Precise positioning, relative to the Y axis of the reference device, of all the means contributing to the drive, to the travel, to the guidance, to the docking and to the welding of the sheet metal strips and to the lifting of the sheet together as and when they are made. 2) In that the vertical position of the scroll rollers (13) of the lifting means (12) is remotely controlled very precisely individually and collectively as a function of the progress of the assembly operations and the sequences imposed by those -this. 3 °) In that the respective position of the internal (91) and external (92) welding devices is permanently indicated very precisely during their use, with immediate indication of the offsets that may appear between the two devices, so that this shift can be immediately canceled, in order to permanently maintain perfect concordance of the internal and external welding points, during the progression of the weld bead in the ledge. 4 °) In that the joining by welding of the roof on the corresponding edge of the upper shell is accompanied by the rotation of the assembly over 360 ° at a controlled speed compatible with the ideal progression of the weld bead. 5 °) In that the welding of the assembly on the bottom (11) is preceded by the pressing on movable cleats, the free edge of the lower ferrule (43) of the disassembly of the scroll rollers (13), the coordinated movement downwards of said movable cleats, until the said free edge of the lower shell (43) is pressed against the circumference of the bottom (11) then the evacuation through the manhole of equipment which cannot be used for this final operation. 2. Device for implementing the method according to claim 1 comprising means for driving, bending (30) and permanent control (60) of the bending and running of the sheet metal strip (41) as well as means of transverse cutout (70) of transverse docking (80) and longitudinal welding (90) of the sheet metal, the means for driving and bending the sheet metal strip (41) consisting of two motorized rollers (31, 32) one of which is fixed (31) and the other (32) is biased towards it by a jack (34) and a movable roller (33) located downstream of the first two (31, 32), the displacement of which is ensured by a jack (35) as a function of the curvature to be given to the sheet, the means for permanent control of the bending and of movement of the strip of sheet (41) being constituted respectively by a proximity detector (50) and a coding wheel (60); the scrolling means being constituted by rollers (13) associated with lifting cylinders (12) distributed regularly over a circumference to constitute a merry-go-round (10) of diameter corresponding to that of the ferrule (42) to be obtained, these rollers (13 ) being intended to gradually support the sheet (41) after bending, during its drive by a motorized roller tractor (100) characterized in that the drive means (31, 32, 34) for bending (33, 35) , transverse cutting (70), permanent control control and scrolling (50, 60), transverse cutting (70), welding (90) and support of the sheet during the scrolling (12, 13) as well that the motorized roller tractor (100) is managed by a programmable controller remotely controllable by a wireless control unit and that the position of the electrodes of the welding devices (91, 92) is controlled by detectors connected to a monitor that measures and af record, in real time, any position differences with a view to their immediate cancellation.