POLYMERIC MATERIAL EXTRUSION NOZZLE AND PRINT HEAD FOR ADDITIVE MANUFACTURING COMPRISING SUCH EXTRUSION NOZZLE

Abstract

An extrusion nozzle of a print head for additive manufacturing, the extrusion nozzle extending about a longitudinal axis and having an insert provided with a through opening and an outer ring; and a connecting member configured to partially accommodate the insert and to define a stop element for the outer ring of the insert and provided with a hole through which the insert protrudes, and a coupling member configured to tighten the outer ring of the insert, the connecting member and a plasticizing cylinder by means of a releasable junction system.

Claims

1. An extrusion nozzle for a print head for additive manufacturing, the extrusion nozzle extending about a longitudinal axis and comprising: an insert provided with a through opening for the passage of polymeric material in a pasty state and an outer ring; and a connecting member configured to partially accommodate the insert and to define a stop element for the outer ring of the insert and provided with a hole, through which the insert protrudes, and a coupling member configured to tighten the outer ring of the insert between the connecting member and a plasticizing cylinder by means of a junction system, wherein the connecting member comprises a cup-shaped body, wherein the cup-shaped body has an annular recess configured to fittably accommodate the outer ring of the insert and define a stop element for the outer ring of the insert; and a funnel-shaped body housed, in part, in the cup-shaped body and configured to be clamped between the plasticizing cylinder and the connecting member.

2. (canceled)

3. (canceled)

4. The extrusion nozzle as claimed in claim 3, wherein the funnel-shaped body is arranged to rest on the outer ring of the insert.

5. The extrusion nozzle as claimed in claim 3, wherein the insert has an inlet port and an outlet port, the inlet port being delimited by a first flared face, said funnel-shaped body being provided with a second flared face flush with the first flared face, the first and the second flared faces having the same inclination.

6. The extrusion nozzle as claimed in claim 3, wherein said funnel-shaped body and said connecting member are conformed to realize an axially symmetrical shape coupling.

7. The extrusion nozzle as claimed in claim 1, and comprising a perforated disc clamped between the funnel-shaped body and the plasticizing cylinder.

8. The extrusion nozzle as claimed in claim 7, wherein the funnel-shaped body comprises an annular recess, within which the outer edge of the perforated disc is partially housed.

9. A printing head for additive manufacturing, the printing head comprising: a plasticizing cylinder an extrusion nozzle made according to claim 1 connected to the plasticizing cylinder; and a releasable junction system for connecting the plasticizing cylinder and the extrusion nozzle.

10. The print head as claimed in claim 9, wherein the plasticizing cylinder comprises an end coupling member configured to be facing and contacting said coupling member; the end coupling member and the coupling member being joined by said releasable type junction system.

11. The print head as claimed in claim 9, wherein the plasticizing cylinder has an annular end recess for accommodating, in part, the extrusion nozzle.

Description

DESCRIPTION OF THE DRAWINGS

[0037] Further characteristics and advantages of the present invention will become clear from the following description of non-limiting examples of embodiment thereof, with reference to the figures of the attached drawings, in which:

[0038] FIG. 1 is a sectional view, with parts removed for clarity's sake and parts indicated schematically, of a print head for additive manufacturing in accordance with the present invention; and

[0039] FIG. 2 is a schematic elevation view, with parts removed for clarity's sake and on an enlarged scale, of a variant of the print head in FIG. 1.

PREFERRED EMBODIMENT OF THE INVENTION

[0040] In FIG. 1, reference number 1 denotes a print head for additive manufacturing. The print head 1 extends along a longitudinal axis 1 and comprises a plasticizing cylinder 2, and an extrusion nozzle 3.

[0041] The plasticizing cylinder 2 comprises an end coupling member 4, in the case shown a perforated flange, configured to be connected to the extrusion nozzle 3 by means of a releasable type junction system 5 which, in the case shown, is a bolted joint; and an end annular recess 6 for accommodating, in part, the extrusion nozzle 3.

[0042] The extrusion nozzle 3 comprises an insert 7 provided with a through opening 8 and an outer ring 9; a coupling member 10 comprising a cup-shaped body 11 configured to partially accommodate the insert 7 and to define a stop shoulder for the insert 7; a central hole 12 to allow the insert 7 to protrude outwardly; and a coupling member 13, which extends about the cup-shaped body 11 and is configured to tighten the ring 9 of the insert 7 between the cup-shaped body 11 and the plasticizing cylinder 2 by means of the junction system 5. In the case shown, the coupling member 13 is defined by a perforated flange and the junction system 5 is defined by a bolted joint.

[0043] The cup-shaped body 11 has an annular recess 14 configured to accommodate the outer ring 9. In essence, the housing has a height slightly lower than the thickness of the outer ring 9.

[0044] The through opening 8 of the insert has an inlet port 15 and an outlet port 16, through which, in use, the polymeric material in a pasty state exits.

[0045] The extrusion nozzle 3 comprises a funnel-shaped body 17 housed, in part, in the cup-shaped body 11 and configured to be clamped between the plasticizing cylinder 2 and the connecting member 10. The funnel-shaped body 17 is arranged to rest on the outer ring 9 of the insert 7. The inlet port 15 and the funnel-shaped body 17 are delimited by respective flared faces which, in the case shown, have the same inclination.

[0046] The funnel-shaped body 17 and the connecting member 10 are conformed to realize an axially symmetrical shape coupling.

[0047] The extrusion nozzle 3 comprises a perforated disc 18 clamped between the funnel-shaped body 17 and the plasticizing cylinder 2.

[0048] The funnel-shaped body 17 comprises an annular recess 19, within which the outer edge of the perforated disc 18 is partially housed.

[0049] In the case shown, the opening 9 is substantially a hole delimited by a cylindrical wall with a given diameter with the exception of the inlet port 15 delimited by a flared face. The nozzle 3 comprises a plurality of inserts, not shown in the accompanying Figures, having the same shape and dimensional characteristics as the opening and inserts having openings with different shapes and dimensions. All the inserts have identical characteristics in shape and dimensions of the outer part that makes them interchangeable with each other.

[0050] The inserts can be replaced because they are worn out or because of operating requirements that require a change in the shape and/or dimension of the opening.

[0051] Similarly, the funnel-shaped body 17 and the perforated disc 18 can be replaced if required.

[0052] With reference to FIG. 2, the perforated disc 18 is omitted, and the face of the funnel-shaped body 17 is connected to the inner face of the plasticizing cylinder 2 instead of having the annular recess 19.

[0053] Finally, it is apparent that the present invention comprises further variants of the disclosed embodiments included in the scope of protection of the appended claims.