IMPROVED BENDING PRESSING MACHINE, PARTICULARLY IN THE PROCESSES OF METAL WORKING

Abstract: Bending pressing machine (A), in which the following is provided: at least one cylinder comprising essentially two heads (3, 4), lower one and upper one and an external jacket (5) held by said heads, welded to the shoulder (a') of the pressing machine's frame (a), and in which while the first one (3) provides connection means (6, 6') for the cylinder feeding, the second one (4) supports a corresponding removable flange (8) allowing the extraction of an internal jacket (7); sideways of the crosspiece (1) for the support of the tool (2), at least two guide points respectively, a first one concerning the upper part of the crosspiece obtained out of a fork-like shape (10) obtained from one of said two heads, and a second one provided along the crosspiece in intermediate position, obtained by engaging to the pressing machine's shoulder, on the top and perpendicularly, a guide (12), provided on both sides with a surface (11) with a low friction coefficient, to which is superimposed, one part of a gib (13), being in its turn associated with the corresponding end of the tool-carrier crosspiece.

Description: DESCRIPTION IMPROVED BENDING PRESSING MACHINE. PARTICULARLY IN THE PROCESSES OF METAL WORKING. Technical Field This invention has for object an improved bending pressing machine, particularly in metal working processes. The innovation finds particular even if not exclusive application in the heavy carpentry sector. Background Art There are different bending presses and they are technologically known. These apparatuses are widely used in the metal and mechanical industry, as for example in the working of metal sheets to obtain differently formed longitudinal sections, the possibility of taking up in turn the same sections in order to subject each of them to a further cycle of bending-pressing is not excluded . As a rule, it is possible to note that a so called bending cycle, consists essentially of the vertical descent of a tool until touching the underlying sheet foil, in carrying out the bending, and then, at the end, going back up to reach the starting position. To carry out the previous phases, the machine is made up of two parts, respectively a first dynamic one, generally regarding the upper part, and a static part, making up the underside of the machine placed on the perpendicular of the dynamic part. Concerning the dynamic part, in the execution of the bending cycle, the tool, made up of a blade differently formed also of the interchangeable type, exclusively effects a vertical to and fro movement on axis Y-Y', said movement being ensured by at least two oleodynamic cylinders, of which one for each part, which determine the descent, the eventual stop, and the ascent of an upper crosspiece which longitudinally supports the tool. In more detail, each cylinder group of a traditional bending pressing machine, is literally joined to the frame or static body of the machine, during the preassembly phase of same and in this particular case each with a corresponding side shoulder of the frame of the pressing machine, by using a series of robust screws. As the forces exerted by the pressing machine are high and innumerable, some of these concern by reflex mainly the cylinder-pressing machine connecting point, reason why it is considered a very critical part, which requires particular care in the realization. Contributing to the small fastening of the screws whose purpose is the joining of the parts, there are some subsidiary fastening means, which vice-versa have the purpose of absorbing the stresses as well as that of bearing the enormous effort on vertical axis that the crosspiece discharges in dynamic condition. Currently, in connection with each cylinder group, the realization of a specular cavity on both surfaces is provided, respectively on one side of the shoulder and on the other on the jacket of the cylinder, in such a way to allow the housing of a spline or transversal key. Regarding the structure of the cylinder, it is a traditional one and includes a jacket engaged to the shoulder, of the type obtained by a casting of cast iron closed on the ends on one side by a sealing flange, on the other by a block provided with means for the feeding of the cylinder. Coaxially to the jacket there is the known shaft, whose end, engages steadily one side of said crosspiece and which in turn supports the tool. In the solution just described some drawbacks are noticeable. These are above all related to the fact of having to associate each cylinder group to the frame of the machine. This involves, besides a certain encumbrance protruding generously on both sides, a specific working in the preassembly, a phase that affects in a considerable and unavoidable way on the time and cost of realization of the pressing machine. Concerning more particularly the cylinder, it has been observed that the realization of the jacket in cast iron involves high melting risks and difficult to be checked, being able to alter the constructional features of same and consequently making the hypothesis of breakage possible, which may stop the productive cycle. Also in a traditional example of bending pressing machine, the crosspiece is presently of the type guided on both sides, a reciprocal, guide means being provided, which interferes with the same. This regards in more detail the fact that with each of the two side shoulders of the frame of the pressing machine, concerning a more or less extended portion, and in logic correspondence, a guide is engaged on the top and perpendicularly, by screw means, provided on both sides with a surface with low friction coefficient, as for example a nylon interchangeable small block or other. The interaction between this part of the machine and the upper tool- carrier crosspiece is allowed by that said guide is overlapped by a part of the gib, plate with a typical "L" like shape, it being engaged always by means of screws, to the corresponding end of the tool- carrier crosspiece. The main problem of this solution, consisting of a single guide of the crosspiece for each part, lies in the fact that because of the enormous load that is distributed perpendicularly in respect to the crosspiece, there results a very critical area, being subjected to yielding also of only one of the guides, causing the deformation of the pressing-fold line. All this affects, mainly after a prolonged use in time, the necessary perpendicularity of the sliding along the axis Y-Y' of the crosspiece. The result, consequently, besides a constant maintenance, cannot be other than the obtainment of a low quality press-bent product, with a high number of scraps. An aim of this invention is also that of avoiding the above- mentioned drawbacks. This and other aims are reached with this innovation according to the characteristics as in the included claims, solving the arising problems by means of an improved bending pressing machine, particularly in the metal working processes, in which the following is provided: - at least one cylinder group including essentially two heads, respectively a lower and upper one and an external jacket held by said heads, welded sideways to the shoulder of the frame of said pressing machine, and in which while the first head provides joining means for the feeding of the cylinder, the second one supports a corresponding removable flange for allowing the extraction of an interchangeable internal jacket; - sideways to the support crosspiece of the tool, at least two guide points respectively, a first concerning the upper part of the crosspiece obtained by a fork-like shape obtained from one of the two heads that make up the cylinder, and a second provided along said crosspiece in intermediate position, obtained by engaging to the shoulder of the pressing machine, on the top and perpendicularly, a guide, provided in both sides of a surface with low friction coefficient, which is overlapped by a part of a gib, being in its turn associated to the corresponding end of the tool-carrier crosspiece. In this way, through the considerable creative contribution whose effect consists of an immediate technical progress different advantages are achieved. Firstly, it is possible to further reduce the assembly times of the machine, avoiding the preassembly phase, which means an evident benefit from an economical view-point. Not only this, but a particularly simplified plant is obtained, above all in relation to the hydraulic part and to the feeding of the cylinders, with a firm conformity with the laws in force, aiming at avoiding breaking risks of the hydraulic joints. A third aspect relates to the encumbrances, which are substantially reduced because of the small size of the cylinder, and of its integration in the machine body. Another advantage, more properly of the cylinder, relates to the fact that melting risks of the external jacket are avoided, while concerning the use of the internal jacket that is of the interchangeable type, it has a high maintenance simplicity in general. Such intervention simplicity is due also to the fact of involving the use of articles commonly available on the market, it results also a discreet flexibility in case in which is necessary to change the piston stroke. Regarding the noticeable advantages in the guide solution of the crosspiece with two points for each side, there is no doubt that there is a perfect perpendicularity in the descent of the tool-carrier crosspiece, along the vertical axis Y-Y', maintaining protracted in time such characteristics, with the elimination of a good part of the maintenance and stop costs caused by the moments of pause for interventions on the pressing machine. In conclusion, all are advantages that allow to obtain a good product, with a better quality- price ratio. These, and other advantages will appear from the following specific description of a preferred solution with the aid of the enclosed schematic drawings, the details of which are not to be considered as limitative but only illustrative. Figure 1., represents a sectional longitudinal view of the cylinder group of which in Figure 2, seen along the axis X-X. Figure 2., represents a plan-view of a cylinder group for bending pressing machines. Figure 3., is a prospect of the upper crosspiece assembly, including on one side one cylinder group as well as some guiding means of said crosspiece. Figure 4., represents a plan-view of the assembly shown in the previous Figure. Finally, Figure 5., represents a sectional view on longitudinal level of a cylinder group and of the guides for bending pressing machines. Referring also to the figures, it can be noticed that a bending pressing machine (A), consists of an upper and of a lower part, the first essentially dynamic with respect to the second static one. An upper crosspiece (1) is part of the first one, vertically movable along the Y-Y' axis in respect to the frame (a) of the bending pressing machine, on whose lower end a tool (2) of the interchangeable type is provided associated longitudinally. The body of the machine (A), provides on the ends, a cylinder group for each side, preferably of the double-action type, which determines the descent and vice versa movement along the Y-Y' axis, of the upper crosspiece (1). Each cylinder group is essentially made up of two heads, respectively a higher one (3) and a lower one (4), which hold a first jacket, external, (5). Both said heads (3, 4) and the jacket (5), are steadily welded to the corresponding side shoulder (a') of the frame (a) of the pressing machine (A). In more detail, regarding the first ones, this is made possible by a specific shape of these same, providing besides the technical part for housing the ends of the jackets (5, 7) as well as the relative gaskets, an extension fork (3', 4'). These, have the same thickness as the corresponding heads (3, 4), and each one is disposed on both sides of said shoulder (a'). In more detail, (see. Figs. 1 and 2) while the upper side of the head (3), includes means (6, 6') for the joining to the feeding system, the underlying part realizes suitable seat jackets, a first external (5) and a second internal (7) or interchangeable liner, being coaxial to said first one. The first jacket (5), is closed on one side by upper head (3), while on the other side by the lower head (4), both immovable, allowing the welding to the shoulder (a') also of said first jacket (5). Regarding the second jacket, or internal liner (7), it can be noticed that it is of the interchangeable type. This is made possible by a flange (8), substantially removable from the lower head (4), thus making it possible to remove both the shaft (9) of the double-action cylinder, and the internal jacket (7). A further characteristic, noticeable in the head (3) is the presence of a feeding duct (14), which communicates with an interspace (15) noticeable between the first jacket (5) and the second (7), said duct (14) by feeding means (6') having the function of allowing the return towards the top of the shaft (9). At least one of said heads (3, 4) of the cylinder group, for each side of the pressing machine (A), in particular the lower head (4), provides, in this case orthogonal to the previous one, a second fork (10) (see. Fig. 4) which must guide the perpendicular movement of a side end of the upper crosspiece (1). Said second guide fork (10), provides on the internal and opposed faces, the association of two interchangeable sliding blocks (11), with low frictional coefficient. Regarding instead the lower part, always of the crosspiece (1), it can be observed that it is driven by second guiding means. These include essentially a plate (12), orthogonally engaged in respect to the shoulder (a 1 ), which supports on both sliding sides two sliding blocks (12') also with low frictional coefficient. To said plate (12) from the side turned toward the outside, the section (13') of the gib (13) shaped like an "L" is superimposed, and which is associated by common screw means directly to the crosspiece (1).

Claims: Claims 1. Improved bending pressing machine, particularly in the metal working processes, characterised in that it provides: • at least one cylinder group essentially including two heads (3, 4), respectively a lower and an upper one and a external jacket (5) held by said heads (3, 4), welded sideways to the shoulder (a') of the frame (a) of said pressing machine (A), and in which while the first head (3) provides means (6, 6') for the connection for the feeding of the cylinder, the second one (4) supports a corresponding removable flange (8) for the extraction of an interchangeable internal jacket (7) ; • sideways to the crosspiece (1) of support of the tool (2), at least two guide points respectively, a first concerning the upper part of the crosspiece (1) and a second underlying the first one, provided along said crosspiece (1) in an intermediate position. 2. Bending pressing machine according to claim 1., characterised in that on both sides of the crosspiece (1) of support of the tool (2), are provided at least two guide points respectively, a first concerning the upper part of the crosspiece (1) and a second underlying the first, provided along the crosspiece (1) in an intermediate position; said first guide means, obtained out of a fork-like shape (10) obtained out of one of the two heads (4) that make up the cylinder; while second means are obtained by engaging to the shoulder (a') of the pressing machine (A), on the top and perpendicularly, a guide (12), to which is superimposed a part of a gib (13), in turn being associated to the corresponding end of the crosspiece (1) tool-carrier (2). 3. Bending pressing machine, according to claims 1. and 2., characterised in that each cylinder group is essentially made up of two heads, respectively a higher one (3) and a lower one(4), which being welded to the corresponding side shoulder (a 1 ) of the frame (a) of the pressing machine (A) provide an extension fork (3', 4'), each of which is disposed on both sides of said shoulder (a'). 4. Bending pressing machine, according to preceding claims, characterised in that while the upper side of the head (3), includes means (6, 6') for the joining to the feeding system, the under part realizes seats for housing the ends, by the interposition of suitable gaskets, of two jackets, a first external one (5) and a second internal one (7), being coaxial to said first one. 5. Bending pressing machine, according to preceding claims, characterised in that the first jacket (5), is closed on one side by the upper head (3), while on the other by the lower head (4), both immovable, allowing the welding to the shoulder (a 1 ) of said first jacket (5). 6. Bending pressing machine, according to preceding claims, characterised in that the second jacket (7) is of the interchangeable type providing a flange (8), removable, engaged to the lower head (4). 7. Bending pressing machine, according to preceding claims, characterised in that in the head (3) a feeding duct (14) is present, which communicates with an interspace (15) noticeable between the first jacket (5) and the second one (7), said duct (14) being joined to some feeding means(6').

Inventors: GASPARINI LUCIANO, GASPARINI, LUCIANO
Applicants: GASPARINI LUCIANO, GASPARINI, LUCIANO
Application year: 1997
Main classification: B21D5
IPC codes: B21D5