ITPN20120069A1 - ELECTRO-WELDED FOLDING AUTOMATIC MACHINE - Google Patents

Description

â € œAUTOMATIC FOLDING MACHINE FOR ELECTRO-WELDED NETSâ €

FIELD OF APPLICATION

The present invention relates to an automatic bending machine for electro-welded meshes, in particular usable in the production of prefabricated components in reinforced concrete.

STATE OF THE PRIOR ART

Modern construction increasingly resorts to automated prefabrication, in order to allow the production of components with very different dimensional and shape characteristics, suitable for specific uses.

The prefabricated components in reinforced concrete are essentially made up of a mixture of concrete, cast in forms or formworks with embedded iron reinforcements having corresponding dimensions and shapes.

The greatest complexity of the production system is constituted by the automatic shaping of the reinforcements, starting from previously produced flat electro-welded meshes. The bending machines currently used employ pins or pawls, which are arranged orthogonally to the axis of the wire to be bent, and bending arms which are operated to wind the wires around the pins at a determined angle. The pins are arranged on a supporting guide, which constitutes the bending axis, and are manually adjustable. A single bending arm, whose size is equal to the maximum width of the net, is controlled by any known energy source to describe an appropriate trajectory that carries out the simultaneous winding of all the wires protruding on the same side of the net.

Of course, it is also possible to control the wires individually, but this solution is suitable only for the production of networks of very limited size as the operating pace is extremely slow.

Therefore, automatic bending systems are currently usable only for regular shaping, and are not able to adequately respond to the demand for components that have complex shapes, for example with bevels, recesses and even internal openings.

When the wires of the electro-welded meshes have not constant pitches, unequal lengths, interruptions of continuity, etc., it is inevitable to proceed with manual processing, which is tiring and even dangerous, as well as requiring long times and high costs.

In fact, continuous machine stops are required to adjust the distance of the pins according to the variable pitch of the net wires.

SUMMARY OF THE INVENTION

The main purpose of the invention is to propose an automatic bending machine for electro-welded meshes, which overcomes the drawbacks of the prior art by creating a solution that provides very precise and reliable results, eliminating the downtime of machine downtime for adjusting the elements. shaping operations.

Furthermore, the bending machine according to the invention achieves the aim of increasing productivity and presenting great operational flexibility, as it can carry out the bending of single wires or multiple wires at the same time, without position constraints on the network plane. electro-welded.

In particular, a further object of the invention is to produce continuous folded sections, starting from wire or metal rod, with a fully automatic variable height, without the need to modify the machine by replacing the shaping operating elements.

Another object of the invention is to allow the production of continuous folded sections also with asymmetrical configuration, that is to say with alternating inclined and vertical sections, as well as with sections having different inclinations and therefore different lengths.

These and other objects are achieved with the machine whose characteristics are defined in the claims which conclude the present description.

DESCRIPTION OF THE DRAWINGS

The purposes and characteristics of the invention will become evident from the following description, by way of non-limiting example, with reference to the attached drawings, in which.

- Figure 1 shows a partial perspective view of an example of an electro-welded mesh folded according to the prior art,

- Figure 2 shows in plan and in two side views an example of an electro-welded mesh folded with an automatic machine according to the invention, - Figure 3A schematically shows a plan view of a folding unit in an automatic folding machine according to the invention,

- Figure 3B schematically shows a plan view of a machine equipped with two opposite bending units, such as that of Figure 3A,

- Figure 3C schematically shows a plan view of a machine equipped with two opposite bending units, such as that of Figure 3B, in which the bending units are mounted on a mobile bridge in the same direction of advance of the net,

- Figures 4A and 4B show the bending unit of figure 3A according to sections A-A and B-B respectively,

- Figures 5A and 5B show, respectively, two alternative details with respect to those of the solution described with reference to Figures 4A and 4B,

- Figure 6A shows a front view of the bending machine for electro-welded meshes with the two repositioning mechanisms of the pins or bending pawls at the right and left ends,

- Figure 6B shows a side view of the bending machine for electro-welded meshes in correspondence with the repositioning mechanisms of the bending pins or pawls,

- Figure 7 shows a perspective view of the mechanisms for repositioning the pins or bending pawls,

- Figure 8A shows the mechanism for repositioning the pins or bending pawls in the rest position,

- Figure 8B shows the mechanism of Figure 8A according to section YY,

- Figure 9A shows the mechanism for repositioning the pins or bending pawls in the operating position,

Figure 9B shows the mechanism of Figure 9A according to section YY.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a partial perspective view of an electrowelded mesh, folded with a machine according to the prior known art. As can be seen, the iron wires or rods 1 have substantially equal lengths, are arranged with a constant pitch, and the sides of the net are regular and linear.

Figure 2 shows, instead, schematically in plan and in two side views an example of an electro-welded mesh folded with an automatic machine according to the invention. As can be seen, this net has the iron wires or rods 1 with different lengths, and with different pitches. Furthermore, not only are the sides of the net irregular, because they have protrusions and recesses with different inclinations, but the net also shows an internal opening A.

Figure 3A schematically shows a plan view of a folding unit U in an automatic folding machine according to the invention, arranged below the sliding plane of the net to be folded.

Figure 3A shows a central bending pin or pawl 2, two bending pins 2-1 arranged on the left side and two bending pins 2-2 arranged on the right side. These bending pins are controlled selectively and independently from each other by a centralized control unit (not shown) of the machine, according to a program depending on the bent net shape to be obtained. Of course, the number of side pins is not binding and depends on the maximum number of wires that need to be bent.

Similarly, figure 3A shows a central bending arm 3, a right bending arm 4 and a left bending arm 4-1; said bending arms are connected to the bending unit and are selectively and independently controlled to move with a compound motion, in a coordinated way with the corresponding bending pins, as will be seen below.

Figure 3A also indicates a mobile central pin holder 5, a mobile right lateral pin holder 6 and a mobile left lateral pin holder 6-1. These mobile pin-holder supports are also controlled independently of each other.

To allow the machine to achieve its main purpose, that is to reach all the bending points or axes of the net, the electrowelded mesh formed by the crossed wires or rods 1 is kept still, while the bending must be able to move rectilinear in both directions in a horizontal plane along two axes orthogonal to each other X and Y, as well as be able to perform a complete rotation in both directions around a rotation axis W, as shown by the respective arrows in figure 3A . These movements are controlled by a drive unit of any type, known per se and not represented in the patent drawings.

Figure 3B, on the other hand, schematically shows a plan view of a machine equipped with two bending units U1 and U2, like the one in figure 3A, opposite each other on the two sides of the net R. In this solution, the net is movable rectilinearly as shown the arrow in the figure along a sliding plane, controlled by any known means (not shown for clarity of drawing) suitable for this purpose.

Figure 3C schematically shows a plan view of the machine equipped with the two bending units U1 and U2 as in the embodiment shown in figure 3B, in which the bending units are installed on a bridge P arranged transversely to the longitudinal axis of the network R The bridge P is commanded to move on two guides G, which are supported on the structure 10 of the machine and which run laterally to the net R and parallel to the longitudinal axis of the latter.

In this type of configuration, the electro-welded mesh is supported and kept in position by suitable supports of the structure 10.

Figures 4A and 4B show the bending unit of figure 3A according to sections A-A and B-B respectively. These figures show the guides 7 of the mobile supports 5, 6 and 6-1, as well as the actuators 8 which control the vertical lifting of the same supports along the Z axis. The control of each actuator 8 is independent and it allows to bring into the bending position, through the mobile supports, only and exclusively those pins which, by position, and / or pitch, and / or quantity, are configured to the wires to be bent. The actuation of each actuator 8 is achieved, for example, by means of a hydraulic circuit equipped with respective solenoid valves (not shown), controlled by the machine control unit. It is essential that the lifting of the actuators 8 be adjusted to such an extent that the folding pins 2, 2-1, 2-2 emerge above the work surface. These characteristics of the invention, combined with the movement of the bending arms 3, 4 and 4-1, which we will see later, allow to carry out the bending of the wires 1 of the net in single, partial, or complete mode.

In Figures 4A and 4B, the numerical reference 9 indicates the sliding plane of the electrowelded mesh, while the reference U indicates the structure that contains all the mechanical components, previously described, which intervene in the folding of the mesh. The whole machine can be mobile or fixed, depending on the type of nets feeding system or on the shape of the shaped reinforcement to be produced. If the whole machine is mobile, it can move along the X, Y and W axes, as mentioned above.

In Figures 3A, 4A and 4B, an actuator member 11 is also indicated, which is operated by any known energy source and not shown, for example an electric, hydraulic or similar motor. The actuator member 11 determines the composite motion of each bending arm 3, 4 and 4-1, by rotating a corresponding crank 12 by means of a shaft 13. Each crank 12 is made integral with the shaft 13 by means of a respective coupling pin 14, which is controlled by its own selector 15. The coupling pins 14 and their selectors 15 can be eliminated, as we shall see later, if any split command is used to operate each crank 12.

Each selector 15 controls the composite movement of the bending arms 3, 4 and 4-1 by means of an articulated mechanism which includes a connecting rod 16, one end of which is hinged to the crank 12 by means of a pin 18. The connecting rod 16 is pivoted at its other end in a reaction arm 17 by means of a pin 19. The reaction arm 17 is also hinged on the structure of the bending unit U by means of a pin 21. The reaction arm 17, therefore, making a fulcrum on the connecting rod 16 by means of the pin 19, contrasts the effort generated between the pin or bending pawl 2, 2-1, 2-2 and the corresponding arm 3, 4, 4-1, forcing the arm itself to perform the composite movement in order to follow the appropriate bending trajectory.

In the situation where the pin or bending pawl 2, 2-1, or 2-2 is in the position useful for folding and the arm 3, 4, or 4-1 is in the hooking position under the respective pin or pawl, the trajectory described by the bending arm forces the wire 1 to wind on the cylindrical surface of the pawl itself. The wrapping angle can vary from 0 ° to 180 °.

Figure 4B also shows, in section, a fixed abutment 20 which supports the sliding surface 9 of the electro-welded mesh to be bent. The abutment 20 acts as a contrast to the thrust which is determined on the wire 1 upon bending, by means of the movement of the bending arm.

In the embodiment described so far, the bending machine comprises a single actuator member 11 which controls the different bending arms 3, 4-1, 4-2, selectively according to a program determined by a control unit. Advantageously, however, the folding arms are operated with single and independent controls, as shown alternatively in the solutions of Figures 5A and 5B.

In these solutions, the coupling pin 14 and the selector devices 15 that connect the crank 12 to the shaft 13 are eliminated. Each of the kinematic mechanisms comprising the folding arms 3, 4, 4-1, the respective cranks 12 and the shaft 13 is operated by a respective actuator 111. The set of actuators 111 replaces, by dividing it, the single actuator 11, present in the solution described above with reference to figures 3A and 4A-4B.

A further element characterizing the invention is the automatic positioning device on a support 32 (Fig. 6B), according to the program of the control unit, of the bending kinematics to respond quickly, economically and safely to the needs of reconfiguration of the bending units in response to the different steps between the wires 1 that make up the sections of electro-welded mesh.

The technical solution described below allows the machine to reconfigure itself in the time that elapses between the unloading of the folded mesh panel and the one to be worked without requiring the intervention of personnel.

In fact, as can be seen in the front view in Figure 6A, beyond the margins of a sliding plane S there are two service areas available for the bending units U1 and U2 to carry out the procedures necessary for repositioning the bending pawls. In said areas, fixed on a support 32, as shown in Figure 6B, the mechanisms for repositioning the folding pawls described below are provided with reference also to Figures 7, 8A, 8B, 9A and 9B.

Said mechanisms for positioning the folding pawls are fixed to the support 32 by means of a counter-bracket 33 joined to the lever-holder support 28 by means of an adequate number of bolts. At one end of the lever-holder support 28, by means of a pin 26, an end of the pawl locking lever 25 is fixed, characterized by having a â € œCâ € section. An end of an actuator 27 is fixed to the other end of the lever-holder support 28, the piston of which is connected by means of a pin to the pawl locking lever 25. The free end of the pawl locking lever 25 ends with the pin to release the pawl 24.

The detail illustrated in portion AX of figure 8B, shows the structure made in the base of pawls 2-1 and 2-2 in which a cavity is obtained which is necessary to house the pawl locking pin 22. In the detail illustrated in portion B of the figure 8A, the pawl locking pins 22 are kept in the rest position by the joint action of the thrust of the spring 23 and by the contrasting action of the stops for the pin 29; in this position the pawl locking pins 22 engage in the positioning grooves 30 obtained in the movable supports 6 and 6-1. To move one of the folding pawls 2-1 or 2-2, the folding unit moves laterally to the edge of the work area so that the pawl to be moved is in correspondence with the mechanism to release the pawls. In these situations, the actuator 27 activates the arm 25 so that, by rotating in the direction indicated by the arrow in figure 8B, the pin for the pawl release 24 applies a sufficient pressure on the head of the pawl locking pin 22 to allow it to move back up to release it from the positioning groove 30.

In this configuration shown in figures 9A and 9B the top part of the bending pin 2-1 or 2-2 is located between the two arms of the â € œCâ € described by the section of the pawl locking lever 25 and, in detail BX of figure 9B , it is noted that the pawl locking pin 22 in the rear position is no longer engaged in the positioning groove 30.

Subsequently, the bending unit begins to move in a direction such that the bending pawl reaches the new position. Once the movement necessary to offset the axis of the pawl locking pin 22 and that of the groove 30 has been carried out, the actuator 27 is activated by the control unit so that it rotates the pawl locking lever 25 by the angle necessary to release the pressure on the pawl locking pin 22 but, at the same time, sufficient to keep the top part of the bending pin 2-1 or 2-2 between the two arms of the â € œCâ € described by the section of the pawl locking lever 25. In this way the bending pin 2-1 or 22, remaining stationary, reaches the new position thanks to the movement of the bending unit. Once the new position has been reached, the axis of the bending pin 2-1 or 2-2 coincides with the axis in the selected positioning groove 30 and the contrast spring 23 pushes the pawl locking pin 22 into the position of block. The control unit then controls the actuator 27 so that the pawl locking lever 25 reaches the rest position (Figures 8A and 8B). This procedure is repeated for each of the pawls 2-1 and 2-2 that need to be repositioned.

Once the last necessary repositioning position has been completed, the bending unit resumes the position waiting for the next stretch of net to be folded.

Of course, the solution described above represents only a preferred embodiment of the device for positioning the folding pawls; it is understood that any alternative technical solution can be adopted to obtain the same result.

From the previous description, it is understood that the essential result of the innovation according to the present patent is represented by the possibility of using, for the shaping of electro-welded meshes, a plurality of mobile supports for bending pins and a corresponding plurality of folding arms bending which together constitute single bending units independent of each other.

Consequently, the machine according to the invention allows to drastically reduce the bending times of the electro-welded meshes, as it is possible to operate the bending units with maximum selectivity, that is, individually or in groups.

Claims (7)

â € œAUTOMATIC FOLDING MACHINE FOR ELECTRO-WELDED NETSâ € CLAIMS 1. Automatic bending machine for electro-welded meshes, which are formed by longitudinal and transverse wires (1) having different lengths and / or different pitches, the machine being equipped with at least one bending unit (U) equipped with a plurality of folding pins (2, 2-1, 2-2), operable in the vertical direction, said folding pins being mutually spaced apart by a length equal to the pitch of the net (R) to be folded, and a plurality of folding arms ( 3, 4, 4-1), which can be controlled with a compound movement to wind the wires around the bending pins, said bending unit (U) being mounted on a structure (10) of the machine and being movable in a transverse direction with respect to that of displacement of the net (R), said bending unit (U) being also rotating in both directions around its own vertical axis (W), characterized by the fact that the bending pins (2, 2-1, 2-2) are operated by respective actuators (8) contained in the bending unit (U), which are selectively and independently controlled according to a program determined by a control unit of the machine, and the folding arms (3, 4, 4-1) are connected to the folding unit (U) by means of an articulated mechanism (11-13, 16-19) and are selectively and independently controlled between them from the control unit program, coordinated with the corresponding bending pins. 2. Automatic bending machine for electrowelded mesh, according to claim 1, characterized by the fact that the actuators (8) are able to operate the bending pins (2, 2-1, 2-2) with vertical movement by means of supports (5, 6, 6-1) kept in position by guides (7), called displacement vertically being adjusted to such an extent that the folding pins (2, 2-1, 2-2) emerge above the work surface. 3. Automatic bending machine for electrowelded mesh, according to claim 1, characterized by the fact that the articulated kinematic mechanism comprises an actuator (11), whose shaft (13) controls, by means of a crank (12), a connecting rod (16), which is pivoted in a reaction arm (17) hinged on the bending unit (U) . 4. Automatic bending machine for electrowelded mesh, according to claim 3, characterized by the fact that each crank (12) is made integral with the shaft (13) by means of a coupling pin (14) controlled by a selector (15). 5. Automatic bending machine for electrowelded mesh, according to claim 3, characterized by the fact that a pin (18) is able to allow rotation between the crank (12) and the connecting rod (16), while a pin (19) is able to allow rotation between the connecting rod (16) and the reaction arm ( 17). 6. Automatic bending machine for electrowelded mesh, according to claim 2, characterized by the fact that the supports (6, 6-1) of the bending pins (2-1, 2-2) are provided at the top with positioning grooves (30), in which the locking pins (22) are selectively engaged, stressed by springs and fixed to the respective folding pins (2-1, 2-2), said locking pins (22) being operated by respective motorized arms (24-27) which are hinged on a support (28) integral with the structure (10) of the machine. 7. Automatic bending machine for electrowelded mesh, according to claim 1, characterized by the fact that there are two folding units (U1, U2), mounted on a bridge (P) which is arranged transversely to the longitudinal axis of the net (R) and is mobile on two guides (G) supported on the structure (10) of the machine, the guides (G) run laterally to the mesh (R) and parallel to the longitudinal axis of the latter.