JP2021030629A - Hot end for 3d printer, air heater, unit, and 3d printer - Google Patents

Abstract

To provide a hot end for a 3D printer, an air heater, a unit, and a 3D printer capable of realizing size reduction and energy saving while obtaining strong bonding between layering interfaces of a modeling material.SOLUTION: A hot end for a 3D printer comprises: a feed part formed with a feed port b to which a modeling material is fed; a melting part having plate-like heating means 2 for melting the modeling material fed from the feed part; a discharge part formed with a discharge port a for discharging the modeling material melted in the melting part; and a cylindrical cover part 4 covering the melting part and exposing the discharge port a. The cover part 4 has a blow-in port 4a for blowing hot air, and a blow-out port 4b for downwardly blowing out the blown-in hot air from periphery of the discharge port a.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hot end (discharge head) for a three-dimensional modeling apparatus (3D printer), an air heating apparatus for a 3D printer, a unit for a 3D printer, and a 3D printer.

In recent years, it has been actively carried out to manufacture a three-dimensional model by a 3D printer using a computer. The Fused Deposition Modeling Method (FDM Method, FFF Method) is well known as a method for forming a three-dimensional model by a 3D printer. The FDM method is a method in which a thermoplastic resin mainly in the form of a filament is heated and melted (melted) inside a hot end having a built-in heater, and laminated while being extruded from the tip of the hot end.

However, when the high-temperature molten resin extruded from the hot end using the FDM method is laminated (deposited) on the resin of the base layer that has already been deposited, the resin of the base layer has already cooled and solidification has started. Therefore, although the base layer and the molten resin laminated on the base layer are fused, there is a problem that the strength of the interface portion of the resin cannot be sufficiently obtained.

Therefore, a 3D printer provided with a heating means for heating the vicinity immediately below the hot-end discharge nozzle has been proposed (Patent Document 1). This heating means constitutes a hot air guide block so as to surround the outer periphery of the nozzle, a gap is provided between the hot air guide block and the nozzle, and the hot air guide block has a surface on the nozzle side and a surface on the opposite side. A through hole for hot air is formed that penetrates between the hot air, and hot air is introduced from the hot air generator through the hot air guide into the through hole for hot air, and the introduced hot air is passed through the through hole for hot air to the hot air guide block. , It is introduced into a gap formed by a space surrounded by a heating block and a nozzle, and hot air is blown toward the vicinity directly below the nozzle. According to this 3D printer, the strength of the laminated interface can be improved, and the unevenness of the surface of the modeled object can be reduced.

JP-A-2017-100304

However, since the heating means of the conventional 3D printer disclosed in Patent Document 1 sends air heated by the hot air generator into the through hole provided in the heating block covering the nozzle, it is heated. The means becomes large-scale, which leads to an increase in the size of the device and also increases the power consumption. As described above, the conventional heating means is completely impractical.

The present invention has been made in view of such a situation, and is a hot end for a 3D printer, an air heating device, a unit, and a unit capable of realizing miniaturization and energy saving while obtaining a strong bond at the laminated interface of the modeling material. An object of the present invention is to provide a 3D printer.

As a result of intensive research to achieve the above object, the present inventor can reduce the size of the melting portion by using a plate-shaped heating means as the heating means for melting the modeling material, and as a result, covers the melting portion. It was found that the hot end equipped with the hot air heating means can be miniaturized and the practicality can be enhanced by blowing hot air to the modeling stage through the cover. ..

Further, the present inventor has found that when an elongated heating head is attached along an air tube to form an air heating device, it can be used as an air heating means for miniaturization and energy saving, and is suitable for a 3D printer.

That is, the present invention relates to the following hot ends (1) to (10), an air heating device, a unit, and a 3D printer.

(1) A supply unit in which a supply port to which a modeling material is supplied is formed, a melting unit having a plate-shaped heating means for melting the modeling material supplied from the supply unit, and a melting unit. A discharge portion formed with a discharge port for discharging the modeling material and a tubular cover portion that covers the melting portion and exposes the discharge port are provided, and the cover portion is a blow port for blowing hot air. A hot end for a 3D printer, which comprises a blowout port for blowing the blown hot air downward from the periphery of the discharge port.

According to the hot end of (1), the cover portion covering the melting portion can be made relatively small by using the plate-shaped heating means, and the safety of the melting portion that becomes hot can be ensured. Hot air can be secured by using this cover portion. Can be sprayed around the molding region (laminated region) to heat the laminated surface while modeling, so that it is possible to avoid increasing the size of the heating means for heating the laminated region. In addition, since the hot air (heated air) blown into the cover is blown downward from the periphery of the discharge port exposed from the cover, the heating temperature of the melting part is not lowered more than necessary, and the inside of the cover is not lowered. By efficiently utilizing the heat generated by the plate-shaped heating means, it is possible to reduce the decrease in the temperature of the hot air blown from the outlet, and the air heating for creating the hot air blown from the outlet can be performed with energy saving. Furthermore, since the hot air flows from the top to the bottom inside the cover and is blown out, the heat of the melting part can be reduced from propagating to the upper side (supply part side), and the clogging of the molding material in the hot end can be reduced. , Good melting and discharging of the molding material can be performed. In addition, since the hot air is blown downward from the periphery of the discharge port, it is possible to discharge and stack in the area surrounded by the hot air, so to speak, in the air curtain, and it is possible to block the influence of the outside air flow. It is possible to perform good lamination.

(2) The hot end for a 3D printer according to (1) above, wherein a plurality of outlets are formed on the lower surface of the cover portion so as to surround the outlet.

According to the hot end of (2), since there are a plurality of outlets, the wind speed of the hot air blown from the outlets can be increased, which can contribute to good stacking.

(3) The hot end for a 3D printer according to (1) or (2) above, wherein a protective plate portion projecting from the outer periphery of the cover is provided below the blow port of the cover portion. ..

According to the hot end of (3), the hot air blown out from the outlet can be released through between the protective plate portion and the modeling stage, so that a relatively wide area around the discharge area is heated. It is possible to increase the speed of modeling.

(4) An air heating device for a 3D printer that heats air, and has an air tube for passing the air, an elongated insulating substrate, and a band-shaped heat generating resistor provided along the insulating substrate. A head is provided, and the heating head is attached so that the insulating substrate is attached in the middle of the air tube along the length direction thereof so that the air can be heated by passing the air through the air tube. An air heating device for a 3D printer, characterized in that it is used.

According to the air heating device (4), the heated air can be taken out simply by passing air through the tube, so that hot air can be easily produced with a small device, which is suitable for mounting on a 3D printer. It is a thing. Moreover, since it is heated by a heating head using a heat generating resistor, it is possible to reduce an increase in power consumption even if it is used for a long time.

(5) A supply unit in which a supply port to which the modeling material is supplied is formed, a melting unit having a heating means for melting the modeling material supplied from the supply unit, and the modeling material melted in the melting unit. The discharge portion in which the discharge port is formed, the melting portion, and the discharge port are exposed, and the blow port for blowing hot air and the blown hot air are blown downward from the periphery of the discharge port. A hot end, an air pump, an air tube that guides air sent from the air pump to the air inlet of the cover, and an air tube in the middle of the air tube. The molding material is melted by providing an air heating means for heating the air passing through the air tube and blowing the heated air introduced into the cover portion from the blow port from the outlet of the cover portion. A unit for a 3D printer, characterized in that an air pump is formed so as to surround the laminated area of the above.

According to the unit (5), it is possible to reduce the size and save energy of the 3D printer.

(6) The filament drying tube arranged directly above the discharge port is further provided, and the drying tube has a hot air blowing port for blowing hot air in the middle of the drying tube (5). ) Described in the 3D printer unit.

(7) The above-mentioned (5) or (6), wherein the hot end is provided with a protective plate portion projecting from the outer periphery of the cover portion below the air inlet of the cover portion. Unit for 3D printer.

(8) The air heating means is a heating head having an elongated insulating substrate and a band-shaped heat generating resistor provided along the insulating substrate, and the insulating substrate is attached along the air tube. The unit for a 3D printer according to any one of (5) to (7) above.

(9) A 3D printer provided with the hot end according to any one of (1) to (3) above.

(10) A 3D printer provided with the air heating device according to (4) above.

(11) A 3D printer provided with the 3D printer unit according to any one of (5) to (8) above.

According to the present invention, it is possible to provide an extremely practical 3D printer that is miniaturized and energy-saving.

It is a partial cross-sectional schematic diagram of the unit of one Embodiment of this invention. It is (A) partial cross-sectional schematic diagram of the unit of another embodiment of this invention, and (B) bottom surface schematic diagram of a hot end. It is a partial cross-sectional schematic diagram of the unit of the embodiment to which the filament drying apparatus of this invention was applied. It is a partial cross-sectional schematic diagram of the unit of the embodiment to which the other filament drying apparatus of this invention is applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the unit of the present invention. The 3D printer unit includes a hot-end HE and an air heating device AH.

The hot-end HE has a nozzle 1 having a discharge portion having a discharge port a formed at the lower end (lower side of the drawing) for discharging the molten modeling material and a melting portion for melting the modeling material, and a filament at the upper end (upper side of the drawing). It is provided so as to surround the barrel 3 having the supply portion formed with the supply port b of the (linear modeling material), the pair of heating heads 2 which are the heating means of the melting portion of the nozzle 1, and the nozzle 1. It includes a tubular cover 4 and a disk-shaped protective plate 5 provided so as to project like a flange from the peripheral edge of the lower end of the cover 4.

The nozzle 1 has a tapered discharge portion provided with a discharge port a at the tip (lower side of the drawing), and a pair of heating heads 2 and 2 are attached to the middle portion above the nozzle 1 so as to face each other in the left-right direction. The part is formed. The upper part of the nozzle 1 has a cylindrical shape formed thick like a brim for attaching the barrel 3, the lower part has a substantially prismatic cylinder (rectangular tubular shape) as if cut from the left-right direction, and the tip portion has a taper. It is provided as follows. A flat surface portion machined from the left and right is further provided in a portion of the nozzle 1 to which the heating heads 2 and 2 are attached, and leads (lines) (not shown) are provided from the heating heads 2 and 2 attached to the flat surface portion. It has been derived. The pair of heating heads 2 and 2 facing each other sandwich the nozzle 1 at both left and right sides of the nozzle 1, for example, through a heat-resistant bonding agent such as cement or by using a bonding material such as a metal wire. As described above, it is pressed against the flat surface portion of the nozzle 1 and fixed.

As the material of the nozzle 1, metals, ceramics and the like can be widely used, but a material having a thermal conductivity higher than that of the barrel 3 is preferable, and a metal is more preferable. More specifically, for example, stainless steel, brass, iron, copper, aluminum and the like can be more preferably used.

The heating head 2 is a heating means for melting the modeling material (filament) pushed into the melting portion of the nozzle 1, and is formed on, for example, a rectangular plate-shaped alumina zirconia ceramic substrate (insulating substrate) and the surface of the insulating substrate. A strip-shaped thick film-formed heat-generating resistor and two electrodes eccentric to one end along the length direction of the insulating board so as to connect to both ends of the heat-generating resistor on the surface of the insulating substrate. Has. The surface of the heat generating resistor may be coated with a protective layer (dielectric layer) such as glass containing a filler. The heating head 2 is attached so that the surface of the insulating substrate on which the heat generation resistor is not formed faces the flat surface portion of the nozzle 1.

A plurality of heating heads 2 may be mounted by being divided in the length direction of the nozzle 1 (vertical direction in the drawing) so that the plurality of heating heads can be heated and controlled to different temperatures or different elevating temperature patterns. You may. Further, by adding an electrode in the middle (intermediate) of the heating resistor of the heating head 2 and pulling out another lead from this electrode, it is possible to control the two heating resistors separately as two heating resistors 2. The leads may be pulled out and controlled so as to connect the heat generating resistors 2 and 2 in parallel, or the heating heads 2 and 2 may be controlled separately. Further, a plurality of heat generating resistors may be formed vertically on the insulating substrate of the heating head 2 and controlled in common or separately.

The cover 4 is made of, for example, a metal such as aluminum or stainless steel, a heat-resistant resin such as polyimide or PEEK, and has a cylindrical shape such as a cylinder or a square cylinder. The upper and lower ends of the cover 4 are opened, the nozzle 1 is inserted through the upper end opening, the discharge port a is projected from the lower end opening, and the upper end opening is closed by fitting the upper flange portion of the nozzle 1. .. The cover 4 covers the entire side surface of the nozzle 1.

A blow-in port 4a (through hole) is formed in the upper side wall of the cover 4, and a blow-out port 4b is formed in the lower end opening. The blow port 4a is preferably provided at a position corresponding to the upper part of the nozzle in the cover 4 and at a position above the heating head 2 or above the heating head 2. The flange portion on the upper part of the nozzle 1 is joined to the inner wall of the cover 4 by cement or the like. The nozzle 1 and the cover 4 are, for example, the left and right side portions (of the heating heads 2 and 2) of the nozzle 1 and the inner wall of the cover 4 via a bonding agent such as cement, or the nozzle 1 is connected from the outside of the cover 4. It is preferable that it is also fixed on the lower side by screwing it so as to sandwich it with a pair of screws. The cover 4 is formed with a through hole for leading the lead wire connected to the heating head 2 to the outside of the cover 4.

The barrel 3 is provided with a filament supply port b at the upper end, and the lower end is screwed into the flange portion at the upper end of the nozzle 1, so that the supply port b, the passage penetrating the inside of the barrel 3, and the inside of the nozzle 1 are penetrated. A passage (passage) is formed which penetrates the passage and the discharge port a at the tip of the passage in a straight line in the vertical direction. The barrel 3 is made of metal and has a shape in which six disc-shaped heat radiating plates project from a cylindrical peripheral wall, and a heat sink that suppresses the heat of heating by the heating head 2 from being conducted to the supply port b side. It has the function as.

A disc-shaped protective plate 5 is attached to the lower end of the cover 4. The central portion of the protective plate 5 is opened so as not to cover the outlet 4b of the lower end opening of the cover 4, and the discharge port a of the nozzle 1 projects downward from this opening. The material of the protective plate 5 may be, for example, a heat-resistant resin such as PEEK or polyimide, or a metal such as aluminum or stainless steel.

The hot end HE thus formed is vertically installed by attaching the upper end portion of the barrel 3 to the attachment base B via the attachment member 6.

Next, the air heating device AH used for the hot-end HE of the present invention will be described. The air heating device AH is sent from the air tube AC, one end of which is connected to the air inlet 4a of the cover 4 of the hot end HE and the other end of which is connected to the small air pump AP, and the air pump AP to the air tube AC. The heating means 11 for heating the air passing through the air tube AC while the air is being blown into the cover 4 from the air inlet 4a while passing through the air tube AC is provided.

The air tube AC includes a heating pipe 12 at an intermediate portion, introduction tubes 14 at both ends thereof, and a blowing tube 15. One end of the introduction tube 14 is connected to the outlet of the air pump AP, and the other end is connected to one end of the heating pipe 12. One end of the blow tube 15 is connected to the other end of the heating pipe 12, and the other end is connected to the blow port 4a of the cover 4. The air tube AC can be used as a heat-resistant resin tube such as Teflon (registered trademark), a metal tube such as aluminum, ceramic, or a combination thereof. Since the heating pipe 12 is heated by the heating means 11, it is more preferable to use a metal pipe having good thermal conductivity, and the introduction tube 14 and the blow tube 15 are excellent in handling because they are bent and connected. It is more preferable to use a resin tube.

A heating means 11 is arranged in parallel with the heating pipe 12 so that both ends thereof are fixed by the fittings 13 and 13 and are in contact with each other. The heating means 11 fixes a long heating head having an elongated insulating substrate slightly shorter than the heating pipe 12 and a strip-shaped heat generating resistor provided along the insulating substrate to a prismatic base (aluminum). It becomes.

The air heating device AH thus formed is mounted together with the air pump AP on the mounting base B to which the hot end HE is mounted.

Next, the process until the air sent out by the air pump AP is blown onto the surface of the modeling laminate A on the modeling stage ST will be described. The air blown out from the outlet of the air pump AP is introduced into the heating pipe 12 via the introduction tube 14, is heated by the heat generated by the heating means 11 in the process of passing through the heating pipe 12, becomes hot air, and is blown. It is sent to the filling tube 15. The hot air sent into the blowing tube 15 is blown into the cover 4a from the blowing port 4a of the cover 4 of the hot end HE, and passes beside the heating head 2 of the nozzle 1 to reduce the temperature drop of the hot air. , The blowout port 4b at the lower end of the cover 4, that is, the periphery of the discharge port a is sprayed onto the surface of the modeling laminate A on the modeling stage ST. Then, the hot air blown on the surface of the modeling laminate A is blown out through between the protective plate 5 and the modeling laminate A. The protective plate 5 suppresses the relatively cold outside air from hitting the surface of the modeling laminate A, that is, suppresses the influence of the outside air, and at the same time, blows hot air blown from the outlet 4b of the cover 4 to the modeling laminate A. It has the function of spraying on a relatively large area of the surface of the. Further, since the hot air blown from the outlet 4b of the cover 4 is blown out from the periphery of the protective plate 5, dust and cold air (airflow at a relatively low temperature that reduces the adhesion between the layers) during lamination). Can be prevented from reaching the laminated portion, and the decrease in adhesion between the laminated portions can be reduced.

In the hot-end HE of the present invention, when the protective plate 5 is not used, the hot air blown from the outlet 4b of the cover 4 can act as an air curtain surrounding the laminated portion, and allows dust and cold air to enter the laminated portion. Can be prevented.

FIG. 2 shows a schematic diagram showing another embodiment of the unit of the present invention. In the present embodiment, the hot-end HE2 includes two protective plates, a first protective plate 50 and a second protective plate 60, which are attached to the lower end of the cover 4. It differs from the hot-end HE shown in, and is common in other respects. The differences will be described below.

The first protective plate 50 attached to the lower end of the cover 4 has an opening 40a facing the discharge port a at the tip of the nozzle 1 in the center and eight relatively small openings surrounding the opening 40a. It has 40b.

Then, a disk-shaped second protective plate 60 of the same size is provided so as to project and surround the cover 4 from the outer peripheral edge so as to overlap the first protective plate 50 at a slight distance.

Since the outlet 40b of the first protective plate 50 is a small hole (opening), hot air blown into the cover 4 from the outlet 4a is blown onto the surface of the molding laminate A at a high wind speed. The surface of the modeling laminate A can be heated more effectively.

The second protective plate 60 forms a heat insulating space between the second protective plate 60 and the first protective plate 50, heat can be reduced from diffusion from the upper surface of the first protective plate 50, and the surface of the modeling laminate A can be formed. It is possible to suppress a decrease in the temperature of the hot air that is blown.

The first protective plate 50 and the second protective plate 60 may be made of resin or metal. For example, the first protective plate 50 is made of a metal such as aluminum or stainless steel having high thermal conductivity. By using a plate and the second protective plate 60 as a heat-resistant resin plate such as PEEK having low thermal conductivity, the heat generated by the heating head 2 is transferred to the first protective plate 50 via the cover 4 (made of metal). It can be efficiently conducted to the surface, and the heating effect of the surface of the molded laminate A by the first protective plate 50 can also be expected. Further, by making the second protective plate 60 made of a resin having low thermal conductivity, heat diffusion from the upper surface of the first protective plate 50 can be further suppressed.

Next, a modified example of the air heating device of the present invention will be described. As the heating pipe 12 in the air heating device AH of the above embodiment, a linear one is used, but particles and fragments of metal, stone, ceramic, glass, etc. having a large heat capacity are contained in the heating pipe 12. A certain filling member may be put in. By filling the heating pipe 12 with the filling member, the heating pipe can be shortened and the air can be heated to a desired temperature without raising the temperature of the heating means 11.

Further, as another modification of the heating pipe 12, the spiral shape may be formed instead of the linear shape. By arranging the spiral heating pipe so as to be wound around the heating means 11, the length of the passage for heating the air can be increased. Further, a meandering or zigzag groove is formed on at least one side of two ceramic or metal plate members by etching or sandblasting, and these plate members are bonded to each other to form a groove inside the plate body. A meandering or zigzag air passage may be formed and used as a heating pipe. The distance from one inlet to the other outlet of the passage can be increased, and the air can be efficiently heated by the heating means. At this time, when the heating pipe is formed by using ceramic as the plate member, the heating pipe can also be used as the heating means by forming a thick film of the heat generating resistor on the outer surface of the ceramic plate.

Further, the introduction tube 14 may be filled with a granular desiccant such as silica gel. By filling the introduction tube 14 with a desiccant, the air blown out from the air pump AP can be dried and then heated, and this dried hot air is blown downward from the periphery of the discharge port a to form a laminated product. It can be sprayed on the surface, and it is possible to further reduce the decrease in the bonding force at the laminated interface of the modeling material due to moisture.

Further, by providing a filament drying device that dries the filament immediately before supplying it to the hot end HE (barrel 3) and supplying the dried filament to the hot end, it is possible to strengthen the bond at the laminated interface of the modeling material. it can. A specific example of the unit to which this filament drying device is applied is shown in FIG.

The hot-end HE (or HE2) of this specific example is the same as that of the above-described embodiment. The air heating device AH is sent from the air tube AC, one end of which is connected to the air inlet 4a of the cover 4 of the hot end HE and the other end of which is connected to the small air pump AP, and the air pump AP to the air tube AC. The heating means 11 for heating the air passing through the air tube while the air passing through the air tube is being blown into the cover 4 from the air inlet 4a is provided.

The air tube AC has an introduction tube 14 having one end connected to the air pump AP and the other end connected to one end side of the heating pipe 12 via a joint JT1 and a heating pipe 12 arranged side by side along the heating means 11. One end is connected to the other end side of the heating pipe 12, and the other end is connected to one end side of the blowing tube 17 via a T-shaped branch joint JT2 (which may be a Y-shaped branch joint). A connecting tube 16 to be connected and a blowing tube 17 whose other end side is connected to the blowing port 4a of the cover 4 are provided.

The other end of the introduction tube 14 may be directly connected to one end of the heating tube 12 without using the joint JT1. Further, the introduction tube 14 may be filled with particles of a desiccant such as silica gel in order to dry the air sent to the heating pipe 12.

The air tube can be used as a heat-resistant resin tube such as Teflon, a metal tube such as aluminum, ceramic, or a combination thereof. Since the heating pipe 12 is heated by the heating means 11, it is more preferable to use a metal pipe having good thermal conductivity, and the introduction tube 14, the connecting tube 16 and the blowing tube 17 are bent or connected. It is more preferable to use a resin tube that is easy to handle. Further, as the joint JT1 and the branch joint JT2, for example, those made of heat-resistant resin such as polyimide and PEEK and those made of metal such as aluminum can be preferably used.

A heating means 11 is arranged in parallel with the heating pipe 12 so that both ends thereof are fixed by the fittings 13 and 13 and are in contact with each other. The heating means 11 uses a long heating head having an elongated insulating substrate slightly shorter than the heating pipe 12 and a strip-shaped heat generating resistor provided along the insulating substrate on a prismatic base (aluminum, PEEK). It is fixed.

Next, the filament drying device FD will be described. The filament drying device FD has a drying part (first drying tube 19 + branch joint JT3 + second drying tube 20) for drying filaments and an air heating part (air pump AP + introduction tube 14 + joint) for blowing hot air into the drying part. JT1 + heating pipe 12 + heating means 11 + connecting tube 16 + branch joint JT2 + branch tube 18).

In this specific example, the air heating device AH is also used as the air heating unit. That is, the air sent from the air pump AP is heated by the heating means 11 to make hot air, and while being guided to the inside of the cover 4 (blow port 4a) of the hot end HE, from the branch joint JT2 to the branch tube 18. It is branched and introduced into the dry part. Of course, an air heating unit may be provided separately.

The branch tube 18 is a branch joint JT2 provided between the connecting tube 16 and the blowing tube 17, and a branch joint provided between the first drying tube 19 and the second drying tube 20 of the drying portion. Connect with JT3 and blow hot air into the drying part. The lower end of the second drying tube 20 is arranged directly above the supply port b of the barrel 3. Of the three branches of the branch joint JT3, the opening to which one end of the branch tube 18 is connected is regarded as a hot air blowing port. The branch tube 18 is filled with particles of a desiccant such as silica gel, if necessary.

The hot air blown into the drying portion from the branch joint JT3 fills the inside of the first drying tube 19 and the second drying tube 20, and then mainly from the upper end port of the first drying tube 19 (through the filament). When present, it is released into the atmosphere (through the gap between the filament and the inner wall of the first drying tube 19).

In this way, immediately before supplying the filament to the supply port b of the barrel 3 of the hot end HE, the filament is passed through the first drying tube, the branch joint JT3, and the second drying tube 20, so that the filament is contained in the filament. Moisture (humidity) can be dried by hot air, and the bond between the laminated interfaces of the melted filaments can be strengthened.

The filament drying device FD branches the air (hot air) heated by the heating means 11 that preheats the air to be blown into the cover 4 of the hot end HE, and dries the filament immediately before being supplied to the supply port b. However, another specific example in which the filament before supply is dried separately by using a drying heating device HT will be described below with reference to FIG. In the other specific example (FIG. 4), the components of the hot-end HE, the air heating device AH, and the like are the same as those of the above embodiment (FIG. 1) or the other embodiment (FIG. 2). It is indicated by the same code.

The filament is wound in the filament box FB, and the tips are the first to third supply tubes 21 to 23, the drying heating device HT (heating pipe 120 + heating means 110), and the T-shaped (three-pronged) branch joint. Through the JT4, it is guided to the supply port b of the barrel (supply unit) 3 and is guided to the hot end HE. The inside of the filament box FB is preferably dried with a desiccant such as silica gel.

The filament derived from the filament box FB passes through the third supply tube 23 and is introduced into the heating pipe 120 to which the tip of the third supply tube 23 is connected. In the heating pipe 120, heating means 110 are arranged side by side by attachments 130 and 130 along the length direction thereof. The heating pipe 120 is heated to a predetermined temperature by the heating means 11 and heats the filament passing through the heating pipe 120.

The filament exiting the heating pipe 120 passes through the second supply tube 22 to which the tip of the heating pipe 120 is connected, and is connected to the branch joint JT4 and the branch joint JT4 to which the tip of the second supply tube 22 is connected. It is guided into the first supply tube 21 and supplied into the hot end HE from the supply port b. The tip of the first supply tube 21 faces the supply port b.

One end of the suction tube 24 is connected to the remaining three-pronged branch port of the branch joint JT4, and the other end of the suction tube 24 is connected to the vacuum pump VP. The vacuum pump VP serves as a duct that sucks and discharges the air that has entered from the rear end of the third supply tube 23 through the suction tube 24 from the inside of the heating pipe 120 through the inside of the second supply tube 22. That is, the supply tube before the filament is supplied to the supply port b so that the air that has deprived the filament of moisture in the heating pipe 120 to the second supply tube 22 is cooled so that the moisture does not return to the filament again. It keeps removing from the inside.

As described above, in the present invention, the filament drying device FD is configured to allow the filament to pass through the air stream of heated air. In this way, if the filament is supplied to the hot end while being dried using the air flow of heated air, the filament can be used after being effectively dried. Therefore, the filament can be used in a drying case (filament box). ), It is possible to form a modeled product in which the bonding at the laminated interface of the filament is much higher than when it is taken out from the inside and used.

HE, HE2 Hot end 1 Nozzle a Discharge port 2 Heating head 3 Barrel b Supply port 4 Cover 4a Blow port 4b, 40b Blow port 5 Protective plate AH Air heating device AC air tube 11 Heating means 12 Heating pipe 14 Introduction tube 15, 17 Blow-in tube 16 Connecting tube 18 Branch tube 19 1st drying tube 20 2nd drying tube 21 1st supply tube 22 2nd supply tube 23 3rd supply tube 24 Suction tube AP air pump VP vacuum pump FB Filament box HT Heating device for drying 50 First protective plate 60 Second protective plate JT1 joint JT2, JT3, JT4 Branch joint

Claims (11)

A supply unit with a supply port to which the modeling material is supplied,
A melting unit having a plate-shaped heating means for melting the modeling material supplied from the supply unit,
A discharge portion formed with a discharge port for discharging the molding material melted in the melting portion, and a tubular cover portion that covers the melting portion and exposes the discharge port are provided.
The cover portion is a hot end for a 3D printer, characterized by having a blow-in port for blowing hot air and a blow-out port for blowing the blown hot air downward from the periphery of the discharge port. The hot end for a 3D printer according to claim 1, wherein a plurality of outlets are formed on the lower surface of the cover portion so as to surround the outlet. The hot end for a 3D printer according to claim 1 or 2, wherein a protective plate portion projecting from the outer periphery of the cover is provided below the blow port of the cover portion. An air heating device for 3D printers that heats air.
It is provided with an air tube for passing air, and a heating head having an elongated insulating substrate and a band-shaped heat generating resistor provided along the insulating substrate.
The heating head is attached so that the insulating substrate is attached in the middle of the air tube along the length direction thereof, and the air can be heated by passing the air through the air tube. An air heating device for a 3D printer as a feature. A supply unit in which a supply port to which the modeling material is supplied is formed, a melting unit having a heating means for melting the modeling material supplied from the supply unit, and the modeling material melted in the melting unit are discharged. A discharge port in which a discharge port is formed, a blow port for exposing the discharge port while covering the melting portion, and a blow port for blowing hot air, and a blowout for blowing the blown hot air downward from the periphery of the discharge port. With a hot end, which has a tubular cover with a mouth,
With an air pump
An air tube that guides the air sent from the air pump to the air inlet of the cover portion, and
An air heating means for heating the air passing through the air tube in the middle of the air tube is provided.
The feature is that the heated air introduced into the cover portion from the blow port is blown out from the blow port of the cover portion to form an air curtain surrounding the laminated region of the melted molding material. 3D printer unit. Further provided with a filament drying tube arranged directly above the discharge port,
The 3D printer unit according to claim 5, wherein the drying tube has a hot air blowing port for blowing hot air in the middle thereof. The 3D printer unit according to claim 5 or 6, wherein the hot end is provided with a protective plate portion projecting from the outer periphery of the cover portion below the blow port of the cover portion. The air heating means is a heating head having an elongated insulating substrate and a band-shaped heat generating resistor provided along the insulating substrate, and the insulating substrate is attached along the air tube. The unit for a 3D printer according to any one of claims 5 to 7. A 3D printer having the hot end according to any one of claims 1 to 3. A 3D printer provided with the air heating device according to claim 4. A 3D printer provided with the unit for a 3D printer according to any one of claims 5 to 8.

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