FR2817500A1 - SYSTEM FOR DETECTING THE FORMATION OF PLASTIC BLOCKS AT THE NOZZLE OF A PLASTIC INJECTION PRESS WHILE THE LATTER IS IN PRODUCTION WITH A MOLD - Google Patents

Abstract

The invention concerns a system for detecting formation of a bottleneck caused by plastic material leakage at the nozzle of a plastic injection press when the latter is operating with a mould. A system of sensors (7, 24) placed around the plastic injection press nozzle (3) enables via the surface supporting the parts (10) to detect a plastic material leakage which forms a bottleneck (22) at the start of its formation while the sheath of the press is supported on the nozzle reception inlet of any mould (20) mounted therein and in the course of production. Said system is also designed for simple replacement of the sensors (7, 24) supplied with low voltage for safety reasons.

Description

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The present invention relates to a device which makes it possible to detect the formation of a plastic plug between the nozzle of the barrel of a plastic injection press and the receipt of the mold nozzle installed therein.

Indeed, the significant pressures as well as the temperatures which the nozzle or the nose undergoes the injection sheath of these presses, cause this nozzle or nose to deteriorate in the more or less long term (crushing, deformation).

In addition, this phenomenon is accentuated by the various mold changes carried out on these presses and it is also sometimes the receipt of the mold nozzle which is damaged.

Although the tip of the nozzle is convex and the nozzle receipt concave, if one of the two is in too bad condition, the material infiltrates outward, and like plastic which is no longer in contact direct with the heating collars hardened on its surface, the hot material flows from the inside, travels slowly by coating all the heating collars, thus causing production stoppages, as well as replacements of these heating collars (torn wires ).

All of the heating collars are surrounded by safety covers, visibility is zero even if the nozzle cover is fitted with a transparent plastic window.

It quickly becomes covered with molten plastic particles and becomes opaque.

Being able to detect the formation of plastic from the start therefore has a real advantage.

These detectors act as push buttons.

The accompanying drawings illustrate the invention.

Figure 1 shows the front of the sheath (1) of a plastic injection press, as well as the pot (2), the nose or nozzle (3), all of the heating collars (4) and also the electrical wiring of the collars (5) We see a part (6) which serves as a support for the detectors (7).

The support (6) is made of metal, while all of the parts that make up the detectors (7) can be either made of metal (alloy or other) or of thermosetting plastic.

Inside the detectors (7), there is an electrical contact so that if plastic material pushes on the parts (10) which come out of the detectors (7), this causes these detectors to come into contact. (7).

For safety reasons, the assembly is supplied with low voltage electricity. The electrical supply (8) of the detectors (7) is designed to resist! a coaiem We also see in Figure 1 that the parts (10) of the detectors (7) are sufficiently spaced from the heating collar of the nozzle (3) so that the plastic which will push on it is hard enough to establish contact.

The detector system (7) must also be fairly sensitive.

The detectors (7) are individually connected to each other on a power cable (9) Figure 1 is presented with two detectors (7), but there can be more In Figure 2 we see that the support (6) is in fact a collar held tight by a screw (12) screwed on the legs (13) which form an integral part of the support (6).

Any type of diameter can be provided for the support (6).

We therefore see the nozzle (3) and the parts (10) from the front.

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- .. It can also be seen that the parts (14) of the support (6) allow a detector (7) to be quickly replaced by a simple casing system.

In Figure 3 we see a control box (l9) provided with an on / off button, an audible warning (15), a live indicator, a warning light (16) and the cord 'power supply (9) for detectors (7).

This box (19) will be fitted inside the kit allowing the detectors (7) to be supplied with low voltage as well as all the electronics necessary for the operation of the assembly.

This invention can be included from the very design of any machine for which it would prove useful and necessary.

This system can be designed to stop the production of the machine or simply prevent a plastic plug from forming.

Figure 4 shows the assembly shown in Figure 1 resting on the fixed part (20) of a mold, it is equipped with its centering washer (21) and is supposed to be clamped on the fixed plate of a press plastic injection. This FIG. 4 presents a plug (22) of plastic material in formation and coming to bear on the part (lao) of a detector (7).

Detect from the start, this plug has no possibility of progressing if there is intervention.

FIG. 5 presents three variants, one of which with a part (23) which, in place of the parts (10) and for a better bearing surface, circles the nozzle (3) presented here from the front.

This variant allows a broader detection.

Another variant has a part (25) which, unlike the part (6), allows the adaptation of four detectors (7), the cable (9) will be provided for four connections. However, supports (6,25) can be provided for a number of detectors (7) as desired.

The last variant has longer detectors (24) than the detectors (7) which prevent the creation of a plastic plug earlier. They are adjustable in length.

Claims (7)

- 1 CLAIMS  1) Detector device (7. 24) like push buttons characterized by the fact of permes the detection of plastic plugs (22) at the nozzle (3) of injection of a material injection press plastic and this while it is in production with a mold (20) provided for this purpose 2) Device according to revendic.tmon 1 caracténsc by f; nt that the detectors (7, 24) can be quickly replaced by a housing system 3) System device according to claims 1 and 2 characterized in that for safety reasons the detectors (7, 24) are supplied with low voltage. 4) System device according to your claim t characterized in that the detectors (24) are adjustable lengths. 5) System device according to rc \ cnd! cation 1 characterized in that the supports (6, 2S) of detectors (7, 24) can be designed for the use of a number of detectors (7, 24) as desired. 6) System device according to rc \ cndlcanon 1 characterized by the fact that detectors (7, 24) can be coupled together by the nmtermcdl of a picce (23) which goes around the nozzle (3) of the sheath (l) of the injection press. 7) System device according to rc \ cndlcaUon 1 characterized by the fact that it can be integrated from the design of a machine