3D PRINTING EXTRUDER DEVICE

Description

DESCRIPTION of the industrial invention entitled: “3D printing extruder device” by: NUGAE Srl, of Italian nationality, Contrada Internicola Snc - 98040 Roccavaldina (ME) Designated Inventor: BELVISI Francesco Filed on: August 29, 2024 **** DESCRIPTION TEXT Field of invention The present invention relates to an extruder device for 3D printing, of the type configured to be fed with granules of extrusion material. In particular, the invention relates to an extruder device for 3D printing of type including: - an extruder body, including an extrusion cylinder defining a main axis of the extruder device, and having an input end and an outlet end equipped with an extrusion nozzle, - one or more heating elements associated with the extrusion cylinder, for heat the extrusion material as it proceeds within the extrusion cylinder towards the extrusion nozzle, - an extrusion screw rotatably mounted within the extrusion barrel, for advance the extrusion material into the extrusion cylinder, - an electric motor-reducer group carried by the extruder body, for control the rotation of the extrusion screw, and - a hopper for feeding granules of extrusion material to called extrusion cylinder. Known technique 3D printing extruder devices with the characteristics indicated above have been known and used for a long time. In conventional solutions, the aforementioned hopper for feeding the extrusion material granules is prepared outside the extruder body, which places a limit on the maneuverability of the extruder device, it being necessary to keep the hopper in a substantially vertical position, to ensure the correct feeding of the granules of extrusion material within the extruder body. The present invention stems from the need to overcome the above mentioned drawback, by creating an extruder device that can be moved by making it assume any position and orientation. Purpose of the invention It is therefore an object of the present invention to to build a 3D printing extruder device that is capable of operating correctly and efficiently in any position and orientation. A further object of the invention is to realize the above mentioned lens with an extruder device having a relatively compact structure simple and low cost. A further object of the invention is to provide a device extruder of the type indicated above which has a high efficiency of operation, thanks to a better flow of the extrusion material granules inside the extruder device, with a reduction in feeding time of the granules and a consequent increase in the productivity of the device. A further object of the invention is to provide a device extruder of the above-mentioned type in which the feeding of the granules of material extrusion in the extruder cylinder is guaranteed efficiently, continuously and stable, even when the extruder device is in a position where The feeding of the granules is not aided by gravity. A further object of the invention is to provide a extruder device of the above-mentioned type in which the quality of the extrusion process 3D printing has improved, thanks to a more uniform feeding of the granules extrusion material inside the extruder device. A further object of the invention is to provide a extruder device of the above-mentioned type which is equipped with a system highly efficient temperature control. Summary of the invention In order to achieve one or more of the above-mentioned purposes, the invention has for the object is a 3D printing extruder device having the characteristics indicated at the beginning of this description and further characterized by the fact that: - the extruder body comprises a hollow main core, having a first end rigidly connected to the electric motor-reducer group and a second end, opposite to the first end, to which the end of is connected extruder cylinder entrance, - the hollow main core has a through cavity within which is arranged a drive shaft that connects the electric motor-gearbox group to the aforementioned extrusion screw, - the hopper for feeding the granules of extrusion material to said extrusion cylinder is defined by a lower portion of the internal cavity of the main core, having a substantially tapered configuration conical, whose axis substantially coincides with the main axis of the device extruder, - the main core has an inlet for the granules, configured to be connected to a tube for supply by a flow of pressurized air of granules of extrusion material, said inlet being configured and arranged to feed the granules in a substantially straight direction tangential within an upper portion of the internal cavity of the core main one which is configured as a circumferential channel. Thanks to the above mentioned features, the extruder device according to the invention is able to operate correctly and reliably even when it has an orientation such that gravity does not assist the movement of the granules towards the extrusion cylinder. Some of the known devices can operate correctly even in inclined condition, but not in directions that do not favor the sliding of the granules of material. In the extruder device according to the invention, the granules of material extrusion are fed directly into the core cavity main cable of the device by means of a tube into which the granules are forced by a flow of pressurized air. The granules enter in a tangential direction into the the aforementioned upper portion of the internal cavity of the main core which is configured as a circumferential channel, after which they are fed to the extrusion cylinder from the coaxial central hopper defined by the portion bottom of the internal cavity of the main core. In a preferred embodiment, the aforementioned drive shaft It carries a cochlea-like organ located within the internal cavity of the main nucleus, to facilitate the advancement of the granules towards the aforementioned internal hopper coaxial defined by the lower portion of the internal cavity of the core principal. The device according to the invention, unlike known devices, does not includes any mechanical device (such as a vibrator or a paddle) that facilitates the sliding of the material. Generally other extruders can tilt but not in directions that are not they promote the flow of the material granules In our case, however, thanks to the integrated system of conveyor / hopper the material always reaches the mouth and can be "forced" towards the entrance thanks to a propeller integral with the screw. In the preferred embodiment, the main body is associated with a body auxiliary carrying an outlet for the flow of air supplying the granules, and an inlet for a flow of air to cool the outer surface of the main core. The aforementioned auxiliary body output is associated with a filter and a filter and a fan are associated with the aforementioned auxiliary body entrance activation of a flow of cooling air around the outer surface of the main core, which is preferably equipped with fins to facilitate the exchange thermal with the flow of cooling air. Still with reference to the preferred form of implementation, the nozzle of extrusion is associated with a device for emitting a flow of air temperature controlled, configured in the form of a surrounding toroidal volume the extrusion nozzle and having one or more openings arranged circumferentially to emit an annular flow of air, to control the temperature of the area of printing. The aforementioned toroidal volume is provided with a duct of cold air supply, in which a cooling device is interposed, and of a hot air supply duct, in which a device is placed heater. The heating elements associated with the extrusion tube are for example in form of heating bands surrounding the extrusion tube and in turn protected from a protective casing. Thanks to all the above mentioned features, the invention is able to meet all the objectives that have been specified above. Detailed description of a preferred form of implementation Further features and advantages of the invention will result from the description that follows with reference to the attached drawings, provided for information purposes only non-limiting example, where: - Figure 1 is a perspective view of a preferred embodiment of the extruder device according to the invention, - Figure 2 is an exploded perspective view of the device of Figure 1, - Figures 3, 4 are two elevation views of the device of Figure 1, - figures 5-7 are a sectional view along lines VV, VI-VI and VII- VII of figures 3, 4, - Figure 8 is a perspective view of the main core of the device extruder of figure 1, - figure 9 is a further perspective view of the main core of the figure 8, - figures 10, 11 are sectional views along lines XX and XI-XI of the figure 9, - Figure 12 is a perspective view of a manipulator robot equipped with an extruder device according to the invention. With reference to the drawings, the number 1 indicates as a whole a device 3D printing extruder, configured to be fed with granules of extrusion material. With particular reference to figure 2, the device 1 comprises a hollow main core 2 having a substantially cylindrical through cavity, whose axis, indicated by 2A, defines the main axis of the extruder device. The main core 2 has a first end 20 to which it is connected rigidly a 3-motor electric-gearbox group, including an electric motor 30 and a reducer 31. The main core 2 has a second end 21 (see figures 10, 11) to which the input end 40 of a cylinder is rigidly connected extrusion 4. The extrusion cylinder 4 has an outlet end 41 provided with a dispensing nozzle 5. Still referring to figure 2, the extrusion cylinder 4 is surrounded from multiple heating bands of any known type, to cause heating and a fusion of the extrusion material granules proceeding in the cylinder of extrusion 4. The heating bands 6, in the example illustrated, are protected by a crankcase 7 which has inside it engagement elements (not visible in the drawings) for coupling with corresponding 6A engagement elements carried by the bands heating 6. Inside the extrusion cylinder 4 there is an extrusion screw 8 configured to cause the extrusion material to advance through the extrusion cylinder 4. The extrusion screw 8 is made in one piece, in the example illustrated, with a drive shaft 9 controlled in rotation from the group 3 electric motor-reducer and arranged through a through cavity of the main core 2. In the preferred implementation example illustrated here, the tree of drive 9 carries an auger 10 to aid the advancement of the granules extrusion material towards the extrusion cylinder 4, as will be described later in detail below. With particular reference to figures 10, 11, the main core 2 It has a cylindrical cavity 200 having a lower portion 201 with a substantially conical tapered configuration, whose axis coincides with the main axis 2A of the extruder device. The conical lower portion 201 of the internal cavity 200 of the main core 2 acts as an internal hopper coaxial to convey the extrusion material granules towards an outlet lower 202 (figures 10, 11) communicating with the inlet end 40 of the tube of extrusion 4. The upper portion of the internal cavity 200 of the main core 2 defines a circumferential channel 203 which receives the granules of material extrusion into the central core 2. To this end, the core body main 2 has an entrance opening 22 (see figure 9) through which the granules of extrusion material enter the channel in a tangential direction circumferential 203 defined by the upper portion of the internal cavity 200. Referring to figure 2, the granules are fed to inlet 22 through a tube 11 passed through by a flow of pressurized air. The flow of air in pressure produces a forced feeding of the granules inside the nucleus main 2, via entrance 22. The extrusion material granules enter the channel tangentially circumferential 203 and then continue towards exit 202 of the main nucleus 2 communicating with the extrusion cylinder 4. As visible in figures 6, 7, the auger 10 carried by the shaft of drive 9 is arranged inside the cavity 200, adjacent to the hopper lower 201 and is therefore able to push the granules towards the cylinder of extrusion 4 even when the extruder device has an orientation such as where gravity does not favor the feeding of the granules into the extrusion cylinder 4. With reference to figures 1, 2, the number 12 indicates as a whole a auxiliary body, for example made of plastic material, defining an exit (not visible in the drawings) for the flow of air supplying the outgoing granules from the main core 2 and an entrance (not visible in the drawings) for a flow of cooling air intended to touch the outer surface of the core main 2. The auxiliary body 12 includes a fan 13 for the activation of the cooling air flow of the main core 2. The main core 2 has an external surface preferably having cooling fins, for improve heat exchange with the external flow of cooling air. Still with particular reference to figure 2, to the extrusion nozzle 5 a device 14 is associated with it for the emission of a flow of air at a temperature controlled. The device 14 includes a body 15 in the form of a toroidal volume surrounding the extrusion nozzle 5 and having one or more openings 5A (figures 6, 7) facing downwards (with reference to the drawings) for the emission of a flow annular air at controlled temperature. To this end, the hollow toroidal volume 15 communicates with a first duct 16 for cooling air and with a second duct 17 for heating air. A device is placed in duct 16 cooling 16A of any known type, while in the duct 17 there is interposed a 17A heating device of any known type. With further reference to the figure 9, the main core 2 has an additional opening 23 for assembly of an electrical connector intended to be connected to a cable 24 (figure 2) including a power supply line and one or more lines for data communication. As visible in figures 8, 9 and 11, the body of the main core 2 has walls including inspection windows 25, which allow you to check the correct feeding of the extrusion material granules into the extruder device. Figure 12 illustrates the extruder device 1 in the condition of use in to which it is carried by a manipulator robot 300 of any known type. To this end, a flange 301 is also rigidly connected to the main core 2 (see figure 1) for connection to a robot wrist. Naturally, without prejudice to the principle of the invention, the details of construction and forms of implementation may vary widely from as described and illustrated purely by way of example, without thereby departing within the scope of the present invention, as defined in the appended claims.

Claims

CLAIMS 1. A 3D printing extruder device, configured to be fed with granules of extrusion material, comprising: - an extruder body, including an extrusion cylinder (4) defining a main axis (2A) of the extruder device, and having an inlet end (40) and an outlet end (41) provided with an extrusion nozzle (5), - one or more heating members (6) associated with the extrusion cylinder (4), for heating the extrusion material proceeding within the extrusion cylinder (4) towards the extrusion nozzle (5), - an extrusion screw (8) rotatably mounted within the extrusion cylinder (4), for advancing the extrusion material within the extrusion cylinder (4), - an electric motor-reducer unit (3) carried by the extruder body, for controlling the rotation of the extrusion screw (8), and - a hopper for feeding granules of extrusion material to said extrusion cylinder (4),said extruder device being characterised in that: - the extruder body comprises a hollow main core (2), having a first end (20) rigidly connected to said electric motor-reducer unit (3) and a second end (21) opposite the first end, to which the input end (40) of the extrusion cylinder (4) is connected, - the hollow main core (2) has a through cavity (200) within which is arranged a drive shaft (9) which connects the electric motor-reducer unit (3) to said extrusion screw (8), - the hopper (201) for feeding granules of extrusion material to said extrusion cylinder (4) is defined by a lower portion of the internal cavity (200) of the main core (2), having a substantially conical tapered configuration, the axis of which substantially coincides with the main axis (2A) of the extruder device, - the main core (2) has an input for the granules (22),configured to be connected to a tube (11) for feeding by means of a flow of pressurized air granules of extrusion material, said inlet (22) being configured and arranged to feed the granules in a substantially tangential direction into an upper portion (203) of the internal cavity (200) of the main core (2), which is configured as a circumferential channel., 2. Extruder device according to claim 1, characterised in that said drive shaft (9) carries a screw member (10) arranged within the internal cavity (200) of said main core (2), to push the granules towards the aforementioned coaxial internal hopper (201) defined by the lower portion of the internal cavity (200) of the main core (2).

3. Extruder device according to claim 1, characterised in that the main core (2) is associated with an auxiliary body (12) carrying an outlet for the flow of air feeding the granules, and an inlet for a flow of cooling air, to cool the external surface of the main core (2).

4. Extruder device according to claim 3, characterised in that a filter is associated with said outlet of the auxiliary body (12), and that a filter and a fan (13) are associated with said inlet of the auxiliary body (12) to activate a flow of cooling air around the external surface of the main core (2).

5. Extruder device according to claim 1, characterised in that said nozzle (5) is associated with a device (14) for emitting a flow of air at a controlled temperature, configured in the form of a hollow toroidal body (15) surrounding the extrusion nozzle (5) and having one or more openings (15A) arranged circumferentially to emit an annular flow of air.

6. Extruder device according to claim 5, characterised in that said hollow toroidal body (15) is provided with a cold air supply duct (16) in which a cooling device (16A) is interposed and a hot air supply duct (17) in which a heating device (17A) is interposed.