LAVARONI, Giorgio (Via Miani 26, Buttrio, I-33042, IT)
PAOLONE, Rolando (Via Cividale 54, Buttrio, I-33042, IT)
MARTINELLO, Paolo (Via Cesare Battisti 81, Staranzano, I-34079, IT)
LAVARONI, Giorgio (Via Miani 26, Buttrio, I-33042, IT)
PAOLONE, Rolando (Via Cividale 54, Buttrio, I-33042, IT)
CLAIMS
1. A metallic profile straightening system, defining a longitudinal path, comprising a plurality of straightening rollers (1 , 1 ') arranged in series along the direction of said path on essentially and reciprocally parallel first and second shafts, said first shafts (2) being arranged at a greater height with respect to the second shafts so that the first are above and the second are under the path, wherein the first shafts (2) are adjustable in height by means of hydraulic cylinders (4) respectively coupled to ends of said first shafts (2) so as to adjust the inclination of the corresponding straightening rollers (1 ) with respect to the horizontal before beginning the straightening operation.
2. A system according to claim 1 , wherein swivel joints are provided between piston (4') of each hydraulic cylinder (4) and the corresponding end of said first shafts (2).
3. A system according to claim 2, wherein said swivel joints are ball joints (7). 4. A system according to claim 2 or 3, wherein said corresponding end of the first shafts (2) comprises a mobile bearing mounting piece (5).
5. A system according to claim 4, wherein the mobile bearing mounting pieces (5) are adapted to slide by means of sliding blocks (8) on the machine body (9) and turn about pivot fulcrums (10). 6. A system according to any of the preceding claims, wherein there are provided anti-rotation keys (13), fixed to the machine body (9), adapted to be inserted in corresponding seats obtained on bearing mounting pieces (5) thus preventing the rotation allowing an appropriate roller change (1 ).
7. A system according to any of the preceding claims, wherein the straightening rollers (1 , 1 ') are arranged between the bearing mounting pieces of the shafts.
8. A metallic profile straightening method to be implemented in a system according to claim 1 , characterised in that before the beginning of the straightening operations there is provided a step of adjusting the inclination of straightening rollers (1 ) arranged on first shafts (2) with respect to the horizontal. 9. A straightening method according to claim 8, wherein said adjustment step of the inclination provides an opening of metallic profiles in a predetermined number before starting the system at full rate. 10. A straightening method according to claim 9, wherein the inclination angle of the straightening rollers (1 ) with respect to the horizontal has a maximum value of approximately 3°. |
STRAIGHTENING APPARATUS Field of the invention
The present invention relates to a metallic profile straightening apparatus . State of the art After rolling, the obtained profiles are generally transferred to a cooling bed. As a result of the rolling, and specifically as a result of cooling, the metallic profiles display distortions or deviations from the desired profile.
A number of solutions for metallic profile straightening apparatuses are comprised in the state of the art. An example of such solutions is described in document EP1038602. Such straightening apparatus provides straightening rollers or plates overhangingly arranged in series, above and under the product to be straightened, on reciprocally parallel shafts. The upper rollers are fixed, while the position of the lower rollers is adjustable. The adjustment of the gap between the rollers, and therefore of the straightening force, and the adjustment of the inclination of the lower rollers with respect to the horizontal are performed by means of respective and independent hydraulic cylinders.
The gap adjustment cylinder is arranged at a rigid bearing mounting piece of the lower cantilever roller holder shaft. All the bearing mounting pieces supporting the straightening roller holder shafts are rigid.
The inclination adjustment cylinder is arranged, instead, at the free end of the lower shaft. The inclination of the shaft, and therefore of the corresponding straightening roller, occurs by effect of the rotation allowed by the clearance of the main bearings, i.e. by the radial clearances between cylindrical rollers and bearing rings. In overhanging straighteners, the inclination of the shaft is needed to compensate for the deflection of the shaft which is the more pronounced the wider the profile to be straightened. Instead, this is not the case of double support straighteners which, in any case, need a better adjustment of the inclination of the rollers in order to obtain a finished product of better quality. A first disadvantage of the described apparatus is to allow a shaft inclination only of very small extent, lower than 0.5°.
A second disadvantage is represented by the fact of providing fixed upper rollers, not allowing to straightening with better tolerances:
- the asymmetric profiles where different forces occur in the various parts of the profile;
- the wide profiles which are not arranged symmetrically with respect to the machine axis. Furthermore, it is not possible to properly compensate for possible differential wear of the straightening rollers.
A third disadvantage is due to the fact that, being the bearings the elements allowing the inclination of the rollers, they are more subjected to wear by effect of the different distribution of the straightening load on the two races of the front bearing, which entails a more frequent replacement thereof.
The need is therefore felt to provide a straightening apparatus capable of overcoming the aforesaid drawbacks.
Summary of the invention
It is the primary object of the present invention to provide a more flexible straightening apparatus capable of inclining the upper rollers with respect to the fixed lower rollers by means of the independent control of two hydraulic capsules or cylinders connected to corresponding mobile and non-rigid bearing mounting pieces, respectively on the operator side and on the control side, which support the holder shafts of the upper roller. A further object is to implement a straightening method by means of the aforesaid apparatus which provides the adjustment of the inclination of the bearing mounting pieces, and therefore of the corresponding rollers, before starting the straightening operations at full rate. Thus, the present invention achieves the objects illustrated above by providing, according to a first aspect of the invention, a metallic profile straightening apparatus defining a longitudinal path which, according to claim 1 , comprising a plurality of straightening rollers arranged in series along the direction of said path on essentially and reciprocally parallel first and second shafts, said first shafts being arranged at a greater height with respect to the second shafts so that the first are above and the second are under the path, wherein the first shafts are adjustable in height by means of hydraulic cylinders respectively coupled to ends of said first shafts so as to adjust the inclination of the corresponding straightening rollers with respect to the horizontal before beginning the straightening operation.
A second aspect of the invention relates to a metallic profile straightening method, to be implemented by means of the aforesaid straightening apparatus which, according to claim 8, is characterised in that before the beginning of the straightening operations there is provided a step of adjusting the inclination of the straightening rollers arranged on first shafts with respect to the horizontal.
Advantageously, the straightening apparatus or machine, object of the present invention, is provided with swivel joints, preferably ball joints, between the rod or piston of each hydraulic cylinder and the corresponding bearing mounting piece so as to allow an inclination of the upper rollers with respect to the horizontal which may reach a value of 3 °.
With this advantageous configuration, the inclination may be made both clockwise and anticlockwise and its control is ensured by position transducers. The inclination of the upper rollers further allows to:
- straighten the asymmetric profiles where different forces occur in the various parts of the profile with better tolerances;
- straighten the wide profiles which are not arranged symmetrically with respect to the machine axis with better tolerances;
- compensate for possible differentiated wear of the straightening rollers.
A further advantage is represented by the fact that during the roller change, which always occurs at a centre distance of the bearing mounting pieces higher than the maximum straightening centre distance, anti-rotation keys of the bearing mounting pieces, which prevent the pivoting thereof and therefore allow an appropriate roller change, are advantageously activated.
The dependent claims describe preferred embodiments of the invention. Brief description of the drawings
Further features and advantages of the invention will become apparent in the light of the detailed description of a preferred, but not exclusive, embodiment, of a straightening apparatus illustrated by way of non-limitative example, with the aid of the accompanying drawings, in which: Figure 1 is a side view of a part of the apparatus of the invention in operating condition;
Figure 2 is a side view of a part of the apparatus of the invention in roller change position;
Figure 3 is a side view of a part of the apparatus in Figure 2 with released components;
Figures 4a and 4b are views of a component of the apparatus respectively in free position and in secured position; Figure 5 is a top view of the part of the apparatus in Figure 2.
Detailed description of a preferred embodiment of the invention A preferred embodiment of the straightening apparatus of the invention, defining a longitudinal path, comprises a plurality of straightening rollers or plates 1 , 1 ' arranged in series along a direction of said path on essentially and reciprocally parallel first and second shafts. First shafts 2 are arranged at a greater height with respect to the second shafts (not shown) so that first shafts 2 are above and the second shafts are under the longitudinal path followed by profile 3 to be straightened. First shafts 2 are adjustable in height by means of hydraulic cylinders 4, each of these being respectively coupled to the ends of said first shafts 2. Specifically, the coupling of each hydraulic cylinder 4 is provided, by means of a piston or rod 4' thereof, to a corresponding mobile bearing mounting piece 5, i.e. the support which by means of radial bearings 6 supports the straightening roller holder shaft. The second shafts and the corresponding straightening rollers are, instead, fixed. In this apparatus, straightening rollers 1 , 1 ' are arranged between two bearing mounting pieces 5, one on operator side and one on control side. Advantageously, mobile bearing mounting pieces 5 are connected to actuating hydraulic cylinders 4 controlled by means of a ball joint 7 which allows a first predetermined inclination of the bearing mounting pieces 5, and therefore of corresponding rollers 1 , with respect to the horizontal. Rotation pins or fulcrums 10, in the number of two, are provided for this purpose either obtained or fixed on opposite parts of each of bearing mounting pieces 5 along an axis thereof (Figures 3 and 5). The rotation of bearing mounting pieces 5 occurs around one of these pins 10. Fig. 1 shows a first shaft or upper shaft 2 in operating, i.e. straightening, condition exploiting the possibility of inclining by the maximum value of 3° by means of the controlled stroke of hydraulic cylinders 4. Position transducers to control the inclination are provided.
The minimum operating centre distance between upper bearing mounting pieces 5 and lower rigid bearing mounting pieces (not shown) is, for example, of approximately 930 mm.
The maximum working centre distance is, for example, approximately equal to 1250 mm. In the range between minimum and maximum centre distance, of approximately 320 mm, there occurs the possibility of inclining bearing mounting pieces 5, independently on operator side 1 1 or on engine side 12, in virtue of the rotation of the bearing mounting pieces on pins 10. The straightening apparatus of the invention advantageously allows to incline both bearing mounting pieces 5 independently, whereas, until now, in the solutions adopted for this type of machines, the bearing mounting pieces always remained vertical and not inclinable.
Fig. 2 instead shows a first shaft 2 with bearing mounting pieces 5 in the straightening roller 1 change position, with anti-tipping or anti-rotation system of the bearing mounting pieces inserted.
Mobile bearing mounting pieces 5 are suitable to slide by means of runners 8 on machine body 9. Blocks 8, defined as sliding blocks, are plates made of appropriate material and shape arranged between bearing mounting piece 5 and machine body 9 which allow a frequent movement, under load, of the bearing mounting piece. Sliding blocks 8, in the example in Fig. 5, may further comprise anti-rotation protrusions or keys 13.
Fig. 4a shows a bearing mounting piece 5 in position with anti-tipping keys 13 not inserted, therefore in position adapted to allow a maximum inclination of approximately 3°. Fig. 4b instead shows the same bearing mounting piece 5 in position with inserted keys. In this condition, the bearing mounting piece can no longer be inclined because, in order to prevent tipping or rotation, bearing mounting piece 5 is locked to machine body 9 by means of keys 13. By comparing these last two mentioned figures, it is apparent how with a further stroke, for example of approximately 50 mm, keys 13, either fixed to machine body 9 or provided directly on sliding blocks, are inserted in the corresponding seats obtained on the body of the bearing mounting piece thus preventing rotation. Such keys are inserted in the corresponding seats only in the roller change position exploiting the total stroke of cylinders 4, taking upper bearing mounting
piece 5 to a maximum centre distance of approximately 1300 mm.
After inserting keys 13, as shown in Fig. 3, mobile shoulder 14 is free to be released. Shaft 2 and bearing mounting piece 5' do not incline and remain horizontal to allow the optimal roller change position. Fixed shoulder 1 comprises, in addition to radial bearing 6, an axial bearing 6' and a pinion-crown device 16 is provided for the axial adjustment, to be set according to the predetermined inclination angle of shaft 2.
A second aspect of the invention provides the implementation of a straightening system which provides, in a step preceding the beginning of the straightening operation, the adjustment of straightening rollers 1 arranged on first shafts 2. Said adjustment provides for a pass of a number of metallic profiles before starting the system at full rate.
This adjustment is performed only before the straightening operations and the inclination angle remains fixed for a predetermined type of profile during said straightening operations.