Patent Application
20100244347
This invention refers to a device and a system for positioning circular manufactured work pieces of medium and large diameter ranging for example between 1.5 and 5 mm, to be processed in different workstations, such as hollow shells having a cylindrical and/or conical body suitable for the construction of tanks, tubular elements, wind towers or other work pieces that must be positioned and subjected to different processings, such as welding operations while maintaining the work piece in rotation.
For positioning and processing circular work pieces having medium or large dimensions, e.g. for welding cylindrical and/or conical sections in the construction of tubular elements, wind towers or other manufactured work pieces, usually some positioning devices, more simply positioners, are used, of the type having two support points, in which each positioner includes a base frame provided with idle rolls at each end of the manufactured work piece to be processed.
As it is well known, the wind towers for supporting electric generators driven by wind at great heights, comprise a plurality of axially arranged conical or circular sections suitably welded along opposite edges; usually, two large circular sections, each supported by two positioners, are approached and axially aligned until to contact their facing circular edges, having a same diameter, to process them, e.g. for welding.
The two circular sections, in their axially approached condition, are driven to slowly rotate around their longitudinal axis during welding, using large and heavy drive spindles. The positioners substantially are consisting of a simple base frame having a couple of idle rolls to support and slowly rotate the large manufactured circular sections, keeping a working head in a fixed position of a processing line.
This is a very simple system in use since a long time for processing completely metallic carpentry within a suitably equipped factory or steady workstations.
A limitation of these large installations relates to rotation of large spindles provided with a very bulky motor drive, involving the use of stationary workstations in plants having a limited working flexibility under operation point of view. Further this causes the users to assemble the manufactured work pieces always in a same work area; in fact it is very difficult and anti-economical to move the positioners to another work area within a same factory, or directly in a building yard, as this could require the displacement of a whole work line. Positioning and perfect alignment of the circular sections is made difficult involving the use of conventional systems such as wedges, cranes and chains.
The problem is made more complex when the work pieces to be processed have a conical shape, such e.g. in the construction of wind towers; in these cases the ends of two large conical sections to be welded must be precisely approached with one another, as their conical shape compels the operator to tilt slightly them in relation to their conical angle, for keeping their longitudinal rotational axis in horizontal position.
Then the presently existing positioners cannot be easily adjusted for circular work pieces having different diameters; further the tilting of the same manufactured work piece cannot be changed for aligning their opposite ends, perfectly in contact, in particular to coaxially drive them during a processing step.
Further, in the case of conical sections for wind towers, use is made of metal sheets having a thickness comparatively thinner with respect to a mean diameter of the work piece; then they prove to have a suitably flexible and elastic structure that causes their deformation when laid on positioner rolls.
Also eventual circularity errors in the diameter, or ovalization of the manufactured work piece constitutes a disadvantage to be removed when a quick, efficient and automated welding or processing operations are requested, as the approached circular ends of conical sections, if they are not perfectly identical, would involve height differences that must be corrected, especially in manufactured work pieces having large dimensions, and diameters in the range of 2 or 3 meters, or higher, showing a difficult handling when actual positioners are used.
A first object of this invention is to provide a positioning device for circular manufactured work pieces or bodies having large dimensions, and a related positioning system including two or more functionally co-related positioning devices, for handling and a correct adjustment of relative positions among circular manufactured work pieces, keeping their longitudinal axes perfectly aligned, independently from the their cylindrical and/or conical shape.
A further object of the invention is to provide a device and system for positioning circular manufactured work pieces having cylindrical and/or hollow conical bodies to be processed, as previously set for, in which each positioner comprises an autonomous drive system for causing the rotation of manufactured work piece, and in which each positioner can be easily transferred, that is moved in different workstations within a same factory, or in building yards.
A further object of this invention is to provide a device and system for positioning circular manufactured work pieces having large diameters, by which it is possible to use a diameter defect correction device for correcting circularity defects, obtaining consequently an easier coupling, and a more precise and quick welding or processing operations.
According to a first embodiment of the invention, a positioning device has been provided for positioning and driving in rotation a work piece of medium or large dimension to be worked having a circular shape, the positioning device comprising:
a longitudinally extending base frame;
first and second spaced apart roll groups on the base frame, each roll group provided with a support roll for the work piece having a rotational axis, at least one of said roll groups being movably supported in the longitudinal direction of the base frame at a right-direction to the rotation axis of roll;
a drive unit operatively connected to the roll of at least one of the roll groups, to drive in rotation the work piece to be processed; and
control means conformed to horizontally and/or vertically move the roll groups in respect to the base frame.
According to another embodiment of the invention, a positioning system for supporting, processing and driving in rotation at least a first and a second circular work pieces in axially aligned condition, the positioning system comprising:
a plurality of positioning devices, in which each positioning device comprises first and second roll groups each provided with a support roll; and control means for horizontally and/or vertically moving at least one of said roll groups;
a drive unit for rotation of the support roll of at least one of the roll groups of each positioning device; and
an electronic control unit operatively connected to said control means and to the drive units of the positioning devices, said electronic control unit being conformed and programmable for adjusting the horizontal and/or vertical position of the roll groups, respectively the rotation speed of the driven support rolls.
These and further characteristics and advantages of the positioning device and system for driving in rotation medium and large circular work pieces, according to the invention, shall appear more clearly from the following description and drawings related to some exemplary embodiments, in which:
As shown, the positioning device 10 comprises a base frame laid on ground, having lateral walls 11 that parallely extend with one another in a longitudinal direction of the base frame.
The positioning device 10 further comprises spaced apart first and second roll groups 12, each adjustable both in vertical and horizontal direction along the longitudinal axis of the base frame 10, for positioning and driving in rotation a circular work piece having a hollow body 13, partially shown in
Each roll group 12 includes a slider 14 provided with a support roll 15 for the work piece 13 to be positioned and driven in rotation.
Each support roll 15 is mounted on the slider for rotation around a horizontal axis 16, one of the roll being idler while the other one of the support rolls being driven by a gear motor 17.
The space between the axes 16 of two parallely arranged rolls 15 can be adjusted and changed in relation to the diameter at which both rolls 15 come in contact with the hollow body 13 of the work piece to be supported; this can be made in any suitable manner, e.g. by moving one or both the two roll groups 12 on the base frame. To this purpose, according to the present example, the slider 14 of each roll group is slidably supported along guide surfaces of the base frame, e.g. along the upper edges 11′ of the lateral walls 11, as shown; a double screw control device, having left and right handed threads, schematically shown by reference number 18, driven by a motor 19, such as a hydraulic or pneumatic actuator or other suitable drive device, allows to approach and move away the sliders 14 in a controlled manner, adjusting in this manner the space between the rolls 15.
Each roll group 12, in addition to be horizontally movable along the base frame, in a first direction at a right-angle in relation to the roll axis 16, can be vertically moved in a second direction at a right-angle to the rotational axis 16 for adjusting the position in height of the same support roll 15, according to variable exigencies or needs of the positioning device 10.
The adjustment in height of each roll group 12 can be made again in any way and by any suitable means; e.g., in the case shown, the adjustment in height can be made by a hydraulic cylinder 20 or by other lifting means. To this purpose it is advisable to provide each roll group 12 with second vertical guide means.
According to another feature of the positioning device 10, the base frame can be tilted laterally with respect to a horizontal reference plane, e.g. the ground on which the same base frame lays on, lifting the roll group laterally at one or both ends. Again this can be made by using any suitable lifting means; as a solely indicative aim,
Both in relation to the exigency of positioning manufactured work pieces conformed by hollow bodies 13 having a cylindrical or conical shape, and in relation to the possibility to tilt the base frame, it is advisable that the support rolls 15 be provided with a freely and self-orienting tilting system conforming to the cylindrical or conical shape of the work piece 13; this is schematically shown, as an example in
As stated above, the support rolls 15 for the work piece 13 can rock around an axis at a right-angle with respect to their rotational axis; these arrangements, in combination with the raising of the roll groups 12, allow to control the positioning of the work pieces 13 in axially aligned positions, as shown by 13A and 13B in
Each positioning device 10 is completely independent with respect to the other devices 10 which are part of a same positioning system; therefore each positioning device 10 of a system may be easily moved in any working position to establish the work area according to the decision of an operator. They can be also installed in a building yard for allowing a welding and/or other processing operations directly in the use place, with the following advantage of allowing the transport of single work pieces having cylindrical or conical bodies, separately, and successively welding and processing them in the building yard.
The
The circularity correction device, in the shown example, comprises a support structure for a plurality of thrust rolls, e.g. comprising two or more arch shaped self-centering arms 30, hinged at 30′ to the base frame 10; each arm 30 comprises a plurality of angularly spaced apart thrust rolls 31, to contact the outer surface of a work piece or of two aligned work pieces 13 on a prefixed diameter. The thrust rolls 31 are supported in a radially adjustable manner, e.g. by hydraulic cylinders 32, or linear actuators of any type, to be moved to and from the work piece or tower section 13. The arms 30 may be moved by an actuator such as a hydraulic cylinder 30″.
As an alternative, the thrust rolls 31 can be supported in a freely pivotable manner, e.g. by a frame 33 hinged to the rod of a hydraulic cylinder 32, as schematically shown in
The
As shown in the
Always in
There are multiple advantages that can be got both by the positioning devices and the positioning system according to the present invention, in particular:
allow the handling of medium and large cylindrical or conical bodies, in autonomous manner;
large cylindrical or conical bodies, can be correctly positioned by adjusting them in height and/or slope;
two cylindrical or conical bodies can be correctly positioned, aligning their opposite ends, lifting and/or lowering one with respect to the other until it is got the coincidence of their circumferential edges;
the longitudinal axis of both cylindrical and conical bodies can be kept in a perfectly horizontal condition, allowing both bodies to be maintained in an axially aligned condition during rotation;
welding and/or other mechanical operations may be performed on the contacting ends of the bodies of the work pieces, in a completely automatic manner, these operations being made with great difficulties by using conventional positioning systems;
further allow the possibility to correct circularity or ovalization defects, and to make the work more precise and easy, by operations more rapid and precise; in this manner it is completely avoided the use of traditional hoisting devices, such as chains bridge cranes, hoisting trolleys and other;
a control autonomy of the rotational or speed, is also possible for conical or cylindrical bodies, by applying each time a required rotational speed in relation to processing operation.
Owing to above and shown in annexed drawings, it will be understood that, according to this invention, a positioning and rotational driving device and system have been provided for medium and large metal sheet circular work pieces, e.g. for cylindrical and/or conical bodies for the construction of tubular elements, pressure tanks, wind towers and the like, by which said advantages are obtained. Therefore other modifications or variants can be made both in the positioning devices, and in the whole system, or its parts, without departing from the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| MI2009A000506 | Mar 2009 | IT | national |
