MACHINE AND PROCESS FOR BENDING THERMOPLASTIC TUBE

Abstract

A machine and a process for bending filiform thermoplastic material, such as a tube, by using a machine for bending tubes provided with a heating apparatus governed by a programmable control unit with a core body positionable inside the portion of the tube to be bent, suitable for being heated in a sector-by-sector basis, said sectors being independent of each other and heatable independently of each other.

Claims

1. A machine for bending a thermoplastic tube comprising: a tube positioning unit; a bending head provided with a tube block device; at least one die; at least one contrast device; a puller unit connected to a tie rod; a heating apparatus; a programmable control unit configured and arranged for controlling the heating apparatus; and a core body including at least two sectors, wherein each of said sectors of the core body is configured and arranged to be independently heated via the heating apparatus.

2. The machine for bending a thermoplastic tube according to claim 1 wherein, the heating apparatus is governed by the programmable control unit, which gives instructions for selecting the sectors of the core body to be heated.

3. The machine for bending a thermoplastic tube according to claim 1, wherein the heating apparatus comprises an induction equipment comprising an inductor device that includes at least one induction coil.

4. The machine for bending a thermoplastic tube according to claim 1, wherein the core body is configured and arranged to be heated and it is solidly connected to the tie rod.

5. The machine for bending a thermoplastic tube according to claim 4, wherein a series of articulated elements configured and arranged for calibrating the portion of the tube to be bent are positioned at one end of the core body.

6. The machine for bending a thermoplastic tube according to claim 4, wherein the core body is formed of two of said sectors, which are independent of each other.

7. The machine for bending a thermoplastic tube material according to claim 1, wherein the at least two sectors are each provided with a temperature sensor configured and arranged for sending signals representing a temperature to the programmable control unit.

8. The machine for bending a thermoplastic tube according to claim 1, wherein the core body is provided with a device for air cooling of the tube after a portion of said tube has been bent.

9. A process for bending a thermoplastic a tube by means of the machine according to claim 1, comprising the following steps: first step of positioning of the portion of the tube to be bent in a bending area placed between the die of the bending head and the contrast device by the tube positioning unit to which is connected the heating apparatus and a programmable control unit and positioning the core body inside the thermoplastic tube, said positioning being realized by the tie rod connected to the puller unit and said core body being connected to the tie rod, wherein said core body is formed of two sectors which are independent from each other and are each configured and arranged to be heated by the heating apparatus that is controlled by the programmable control unit; a second step of blocking a portion of the tube to be bent by the block device; a third step of heating of the portion of the tube to be bent by the heating device, which heats the portion of the tube to be bent by heating one or more sectors of the core body according to the portion of the tube to be bent via the heating device, wherein said heating device is governed by the programmable control unit which continuously receives from a temperature sensor associated with each sector of the core body, the signal representing the temperature reached by the associated sector subjected to heating by the heating device and/or the temperature of the tube to be bent; a fourth step of retracting the positioner unit out of the bending area when the portion of the tube to be bent has reached the temperature to make the portion of tube to be bent sufficiently plastic to be bent; a fifth step of positioning the portion of the tube to be bent inside a throat of the die and clamping said portion of the tube to be bent by the contrast device (5); a sixth step of bending of the portion of the tube to be bent by the movement of the bending head and calibrating the curve of the portion of the tube to be bent by articulated elements placed at an end of the core body that is opposite to the point of contact of the tie rod with the core body (9); a seventh step of the retracting the core body via the retraction of the extractor unit connected to the tie rod, wherein said core body is connected to the tie rod at the portion of the tube that will be subject to the next step of bending and cooling of the bent portion of tube at the completion of the bending cycle by an air cooling device (12); and an eighth step of releasing the tube block device from the portion of the bent tube, retracting the die and the contrast device and the bending head to a rest position to begin a new bending process.

Description

DESCRIPTION OF THE FIGURES

[0025] FIG. 1 shows a perspective schematic view of the bending area of the machine for bending tubes.

[0026] FIG. 2 shows the moving and positioning portion of the machine for bending tubes during the core body activation phase, in a bidimensional form.

[0027] FIG. 3 shows the portion of the machine for bending tubes related to the structure of the core body, in a bidimensional form.

[0028] FIG. 4 shows the first phase of the process according to the present invention.

[0029] FIG. 5 shows the second phase of the process according to the present invention.

[0030] FIG. 6 shows the third phase of the process according to the present invention.

[0031] FIG. 7 shows the fourth phase of the process according to the present invention.

[0032] FIG. 8 shows the fifth phase of the process according to the present invention.

[0033] FIG. 9 shows the sixth phase of the process according to the present invention.

[0034] FIG. 10 shows the eighth phase of the process according to the present invention.

[0035] FIG. 1 shows the bending area of the machine for bending a thermoplastic tube. Said figure shows a tube positioner assembly (1), a bending head (2) provided with a tube blocking device (3), at least one die (4), at least one contrast device (5), and a heating apparatus (8), preferably an induction one comprising an inductor device such as an induction coil. Such heating apparatus (8) also comprises a programmable control unit (A), not shown in the figures, suitable for governing the heating apparatus (8). Said heating apparatus (8) is integrally connected to the positioner assembly (1).

[0036] FIG. 2 shows a puller assembly (6) suitable for moving a tie rod (7) connected thereto and a core body (9) suitable for being heated and integrally connected to the tie rod (7).

[0037] FIG. 3 shows the core body (9) suitable for being heated and formed of at least two sectors (101, 102) independent of each other.

[0038] FIG. 3 also shows a set of articulated elements (13) suitable for calibrating the portion of the tube to be bent (T1), not shown in the figures, positioned at one end (C) of the core body (9), also provided with an air cooling device (12) for cooling the bent tube (T2); none of said elements is shown in the figures.

[0039] FIG. 4 shows the first phase of the process, whereby the portion of the tube to be bent (T1) is positioned in the bending area interposed between the die (4) of the bending head (2) and the contrast device (5) by way of the positioner assembly (1), which a heating apparatus (8), preferably an induction one comprising one inductor device such as an induction coil, and a programmable control unit (A), not shown in the figures, are connected to. This phase comprises the positioning of a core body (9), not shown in the figures, suitable for being heated, internally to the thermoplastic tube, said positioning being implemented by way of the tie rod (7), not shown in the figures, integrally connected to the puller assembly (6), not shown in the figures, said core body (9) being integral with the tie rod (7). Said core body (9) is formed of at least two sectors (101 and 102), not shown in the figures, independent of each other. Remember that the heating apparatus (8) is governed by the programmable control unit (A).

[0040] FIG. 5 shows the second phase of the process, whereby the portion of the tube to be bent (T1) is blocked by way of the blocking device (3).

[0041] FIG. 6 shows the third phase of the process, whereby the portion of the tube to be bent (T1) is heated by way of the heating apparatus (8), which heats the portion of the tube to be bent (T1), preferably byway of the induction heating of one or more sectors (101 and 102) of the core body (9), not shown in the figures, the latter being internal to the tube to be bent, depending on the portion of the tube to be bent (T1), heating being possible independently for each of said sectors (101 and 102) of the heating apparatus (8), said heating apparatus (8) being governed by the programmable control unit (A), not shown in the figures, which continuously receives a signal that represents the temperature reached by the sectors (101 and 102) submitted to heating by the heating apparatus (8) and/or the temperature of the portion of the tube to be bent (T1) from the temperature sensor (B), not shown in the figures, which every sector of the core body (9) is provided with.

[0042] FIG. 7 shows the fourth phase of the process, whereby the positioner assembly (1) is retracted. Said retraction of the positioner assembly (1) positions it outside the bending area, once the portion of the tube to be bent (T1) reaches a temperature suitable for rendering the portion of the tube to be bent sufficiently plastic for being bent.

[0043] FIG. 8 shows the fifth phase of the process, whereby the portion of the tube to be bent (T1) is positioned inside the throat of the die (4) and said portion of the tube to be bent (T1) is blocked byway of a contrast device (5).

[0044] FIG. 9 shows the sixth phase of the process, whereby the portion of the tube to be bent (T1) is bent thanks to the movement of the bending head (2) and the curve of the portion of the tube to be bent (T1) is calibrated byway of articulated elements (13), not shown in the figures, placed at the end of the core body (9), not shown in the figures, in a position opposite to that of the point of contact of the tie rod (7) with the core body (9), not shown in the figures. For an easy identification of the position of said articulated elements (13), note that they are located in an internal proximity to the tube to be bent (T1), of the position of the gripper (31) of the blocking device (3).

[0045] The process continues with the seventh phase, not shown in the figures, whereby the core body (9) is retracted by way of the retraction of the puller assembly (6) connected to the tie rod (7), said core body (9) being integral with the tie rod (7), up to reaching the portion of the tube that will be submitted to the successive bending phase and the bent portion of the tube (T2) is cooled by way of an air cooling device (12) upon completion of the bending cycle.

[0046] FIG. 10 shows the eighth phase of the bending process, whereby the blocking device (3) is released (3) from the bent portion of the tube (T2) and the die (4) and the contrast device (5) and the bending head (2) are retracted to their rest position in order to start a new bending process.