Extruding press and method for its feeding

Abstract: A method for feeding billets in horizontal extruding presses which comprises the opening of the container (12), the cutting off of the surplus of the extruded billet simultaneously to the supplying of a new billet (13) in line with the container (12) and to a simultaneous withdrawal of the press shank (17) after each extruding operation and with the withdrawl of the main piston (14a); then the advancing of the pusher (16a) for the insertion of a new billet (13) into the container (12) which is still open and the simultaneous withdrawal of the billet shear (15) and of the feeder means for the supplying of the billet (13); the closing of the container (12) when the pusher (16a) retracts and the movement of the press shank (17) on the axis of the container (12); finally the advancing of the main piston (14a) for the inserting of the press shank (17) into the container (12) for the extrusion operation.

Description: The present invention relates to extruding presses for structures in aluminium, light alloys, copper and brass and in particular relates to a method for feeding starting billets in said presses. The present method is especially applied to horizontal extruding presses with a die and with a container having a cylindrical cavity on a horizontal axis with a mouth piece for the insertion of the billet with the help of a pusher. Certain extruding presses are provided with a pusher for the inserting of the billets into the container of the press and with a main piston for the controlling of a press shank for pushing the billes towards the die during the extruding process. Extruding presses which use an extended pusher on the extruding axis placed and retractable inside the main piston whilst the press shank is fitted on a movable slide on the piston in a transversal direction to that of the extruding axis are already known from the prior art. this is so as to Ømove the press shank away from the axis of the container in order to feed a new billet and to insert it inside the container through the advancing pusher. In said presses the billet is usually inserted inside the container when the latter is already closed against the die, after the shearing operation of the surplus of the billet previously extruded. The sequence of movements of the container, of the billet shear, of the press shank and of the exit/re-entry of the pusher in relation to the feeding, inserting and extruding of the billet is however such so as to lead to notable dead or passive periods between one phase and the other, thus bearing negatively upon the actual efficiency of the press. A press, in which even the pusher, like the press shank, is fitted onto a movable slide controlled according to a transversal direction to that of the extruding axis has been proposed in a bid to reduce these dead periods. Even in this type of realization notable dead periods which do not allow for a complete exploitation of the potential of the press are still present. The present invention aims to solve the problem of the dead periods in said presses by drastically reducing them through a more consonant sequence in the movements of the operational parts of the machine in relation to the feeding and inserting of the billets into the container. This object is achieved by a method for the feeding of the billets in horizontal extruding presses of the type having a die, a container and a main pressing piston on a single axis, a pusher extending in the main piston on the same axis as said container and retractable in said piston, a press shank movable in a transversal direction to that of the extruding axis and also in line to and out of line of said container, a billet shear for the cutting off the surplus of the billet as extruded and a feeder means for the supplying of the billets in a position bet-ween the container and main, piston. The method comprises after each extrusion operation the following steps: a. simultaeously retracting the main pressing piston and opening the container by moving it away from the die; b. simultaneously cutting off the surplus of the extruded billet, withdrawing the press shank in a transversal direction out of line with the axis of the container and supplying a new billet in line with the axis of said container; c. simultaneously advancing the pusher for the insertion of the new billet into the container and withdrawing the billet shear and the feeder means for the supplying of the billet; d. simultaneously retracting the pusher within the main piston and closing the container by moving it towards the die; e. moving the press shank in a transversal direction in line with the axis of the container; f. advancing the main piston for inserting of the press shank into the container for the extrusion operation. The here proposed method is applicable to both new presses, with a notable reduction of the dead periods, therefore improving their productivity and to old presses as a modification, again to reduce the dead periods as well as to allow for an extrusion of billets longer than the ones forseen in the initial projects of the original machine. The possibility of extruding longer billets reduces the amount of waste from the shearing of the extruded parts. Furthermore, the press with a movable press shank is more compact with respect to traditional presses when considering billets to be extruded of the same length. In accordance with the present invention, the method will be better illustrated in the following description with references being made to the attached drawings in which: Fig. 1 is a side view of the extruding press in operation; Fig. 2 is the same view as in Fig. 1 with the container open and in the position to begin shearing, to move the press shank sideways and away, and to supply a new billet; Fig. 3 is again the same view as the one in Fig. 1 with the billet shear in the operating position, the press shank not in line with the container and the new billet in line with the latter; Fig. 4 shows the press during the withdrawal phase of the billet shear and the supplying parts of the new billet and the inserting phase of the billet into the container; Fig. 5 shows the press in position to start operating on the new billet; and Fig. 6 is a view of the feeder in a transversal direction to that of the press. The extruding press comprises a die (10) with a horizontal axis which is fitted on a relative slide (11) on the axis of said die, a container (12) with a cavity (12a) designed to receive the billet to be extruded (13) and a main pressing piston (14a) operating in a corresponding cylinder (14) and assisted by lateral pistons (not show). A billet shear (15) is fitted between the die (10) and the container (12) for the final shearing of any surplus of previously extruded billets. Within the main piston (14a) and aligned to said container, a cylinder (16) with an outgoing and retracting pushing rod (16a) in the piston is fitted and designed to insert the billet (13) into the cavity (12a) of the container (12). A pressing shank (17) which is movable in line to and out of line, sideways, upwards or downwards with respect to the extruding axis and designed to enter inside the cavity (12a) of the container (12) when the pressing piston (14a) advances during the extrusion operation of each billet (13) is fitted at the head of the main piston (14). A feeder (18) with grippers (18a) which lift and transfer each billet (13) starting from a hot shearing (19), (Fig. 6) up to the level of the press is arranged in a transversal direction to that of the extrusion axis in a position between the retracted main piston and the open container (12). During the extrusion of the billet which has been fed into the container (12), the latter is movable in closure against the die (10); the press shank (17) is on the axis of the container (12); the main piston (14a) moves forward pushing the press shank (17) into the cavity (12a) of the container for the extruding operation. Said condition is represented in Fig. 1 where it can be noted that the billet shear (15) is then in an inoperable position, that the rod (16a) is withdrawn inside the main piston (14a) behind the press shank and that the new billet (13) is near the press ready to be fed. After the extrusion, with simultaneous movements, the main piston (14a) retracts, withdrawing the press shank (17) from the container (12); the container (12) opens, moving away from the die (10); the billet shear (15) moves towards its operating position (Fig. 2). At this point, whilst the surplus of the billet extruded previously is cut off by the billet shear (15), the press shank (17) is moved to a side, either above or below with respect to the extruding axis, freeing the channel of the pusher rod (16a) and, at the same time, the gripping parts (18a) of the feeder (18) bring a new billet (13) into the space between the head of the main piston (14a) and the open container (12) on the extruding axis (Fig. 3). The pusher rod (16a) then moves forward to insert the new billet (13) into the cavity (12a) of the container (12) which is still open (Fig. 4), in the meantime the billet shear (15) is withdrawn and the gripper parts (18a) of the feeder retract to get another billet. Finally, whilst the container (12) closes in on the die (10), the pusher rod (16a) re-enters the main piston (14a) and the press shank (17) is repositioned on the axis of the container (12) (Fig. 5). Under these conditions the press can start a new extruding operation, repeating the above mentioned sequences once a new billet to be extruded is inserted. It is obvious how the contibution and/or the superimposition of the movements of the different operating members of the press allow to reduce the dead periods, thus increasing the production of the press with the advantage of being able to clearly improve the performance of even old presses.

Claims: A method for feeding billets (13) in horizontal extruding presses of the type having a die (10), a container (12) and a main pressing piston (14a) on a single axis, a pusher (16a) extending in the main piston (14a) on the same axis as said container and retractable in said piston (14a), a press shank (17) movable in a transversal direction to that of the extruding axis and also in line to and out of line of said container (12), a billet shear (15) for the cutting off the surplus of the billet as extruded and a feeder means (18) for the supplying of the billets in a position between the container (12) and main piston (14), characterized in that after each extrusion the method comprises the following steps: a. simultaeously retracting the main pressing piston (14a) and opening the container (12) by moving it away from the die (10); b. simultaneously cutting off the surplus of the extruded billet, withdrawing the press shank (17) in a transversal direction out of line with the axis of the container (12) and supplying a new billet in line with the axis of said container; c. simultaneously advancing the pusher (16a) for the insertion off the new billet into the container (12) and withdrawing the billet shear (15) and the feeder means (18) for the supplying of the billet; d. simultaneously retracting the pusher (16a) within the main piston (14a) and closing the container (12) by moving it towards the die; e. moving the press shank in a transversal direction in line with the axis of the container; f. advancing the main piston (14a) for inserting of the press shank (17) into the container (12) for the extrusion operation. A method as claimed in claim 1, characterized in that it comprises a concomitance and/or superimposition of the movements of the different operating parts of the press for the reduction of the overall dead periods. A method as claimed in claim 1, characterized in that it comprises a sidewards, down or up movement of the press shank (17) at the same time as a vertical or horizontal supplying of the new billet between the container (12) and the withdrawn main piston (14a). A method as claimed in claim 3, characterized in that the supplying and insertion of the new billet (13) into the container (12) is carried out with the container open and during the cutting off stage of the surplus of the billet previously extruded.

Inventors: BERTOLI DOMENICO, BERTOLI, DOMENICO
Applicants: OMAV SPA, OMAV S.P.A.
Application year: 1991
Main classification: B21C33
IPC codes: B21C33, B21C23